Honestly, you guys were a lot more cynical and jaded than Reddit, but that's understandable - I'm getting that way playing this game too. I hope this discussion on how to catch this helps the community.

Original posts: r/truegaming, but removed, r/Games, r/QuakeLive, and ESReality
The simple poll is still up at 1000 responses with ~41% saying Vid1 and 59% saying Vid2. It started with most people thinking my manual aim was the bot, but after some comments appeared explaining their decision, more people chose correctly.

The first video was purely manual aim, and the second video was using the aim assist bot. So, as promised, here are some details on what the bot was doing for me, and potential ways to spot people using this in the wild.

I had the bot configured to only assist in tracking toward targets while left mouse (my fire button) is held down. No wall hacks were used in either recording, and prediction of enemies dying to a specific shot was performed manually. The bot was only locking on to things within about 20 degrees of my center of view. Any snapping to targets outside of that cone (or while fire wasn't held) was done manually, and most of the small adjustment tracking was also performed manually. I use mouse acceleration such that when I move my mouse slowly it would take 17" of mousepad to do a full 360 (very low), but when I'm moving it quickly it caps out at 6" of mousepad to a 360 (medium-high). Thus I can use flicks for snaps, but I can also do smooth tracking for long-range hitscan too.

There is a setting in the aimbot to smooth out the aim, and it goes from 1 to 20. This setting seems to take the distance between your cursor and the target, then close in by 1/x of that distance each frame.

On "1", it locks perfectly on the target (obvious to any spectator, and probably even people being hit). By 6, it starts to lag behind players who dodge too fast but still is better than any human. 20 (which I was using) rarely hits a target on its own, and you have to keep using your mouse to get it on your target, but when your aim gets far away, it makes serious corrections to keep you in the general vicinity of your target. This basically means that it keeps my crosshair close enough to my target to let me focus on minor adjustments, which results in high accuracy with much less effort required.

I've read people saying that it adds 5-15% to their lg accuracy when they set it to the smoothed mode, and I don't doubt it. If you use a lower "smoothing" value, you can surely get closer to 80-100% accuracy.

Good comments from people:

* kylegetsspam: "I'm not a Q3 player, but video #2 has a general feel of "too consistent" to me. If it misses it's not by much and it's quickly back on target, whereas in video #1 there's a couple instances where his aim goes rather wide." - This is as true as it gets. I've fought against people I suspect who use this bot, and it's ridiculous how they keep the lightning bolt within a few inches of your character. You can usually juke real humans.
* NightlyNews: "Video one looks like it overcorrected a lot while acquiring targets and video two undercorrected. Overcorrecting quickly and then dialing back a little is quicker and safer for a human but wouldn't happen (often at one point when the second video was shooting up it overcorrected a very small amount) to bots." - Good observation, but since I'm doing the small adjustments, it's very possible for me to overcorrect with the bot on. Still, the consistent undercorrecting is unnatural for most high level aimers. (see also: DesertGoldfish's post)
* phantamines: "Looking at the aiming is what trips people up most about aimbots, very good shots rarely indicate botting."
* gpt999: also on the topic of movement rather than aim.
* jdwpom: "there's a point at around 8 seconds in where he alternates between targets as they come past each other, then keeps focussing on the one he wasn't originally aiming for. This suggests that he isn't discriminating between targets (as the 'better' tactic is to stick with one person until they're dead, reducing the amount of damage you're likely to take), and is basically aiming at anything that's green and moving." I screwed up by giving that tell - lots of people caught on by this one. I've caught real cheaters in public servers decide to stop using the lightning gun in these sorts of situations (after missing awkwardly between the two targets), which makes it all the more obvious to me.
* JigglyWiggly_: "in the first one he can't hit at all when angles come into play
[url="www.youtube.com/watch?v=F_cri2NZnG0&t=14s""][/url] - Very true - I suck at vertical shafting. The bot doesn't completely fix that, but it definitely helps.
* Bondator: "The thing that convinced me of vid 2 was the vertical mouse movement when following jumping targets. Compare for example 0:13 in vid 1 to 0:41 in vid 2." - I think this is one of the biggest tells of the bot. In Quake, headshots don't matter, so there's no reason to aim up for someone jumping at that angle.
* butsplice: "Its pretty much pointed at the bots waist the entire time. It never really goes higher or lower." - similar to the previous comment.

People also commented that I was playing sloppily with the aimbot, allowing it to be a crutch. This is very true, and I didn't think of that when I was recording. That said, there are people who use this bot and play with more attention in their game.

Now, this is what I've noticed and learned from playing with the bot:

* When aiming at close range, the bot tends to aim at the same height of the target model, even when the target jumps. If a human player is aiming at chest height close up, they are unlikely to make serious vertical adjustments when the crosshairs still end up being at leg/feet height. (Note that the 'height' is configurable, so the bot could be programmed to aim for the head or the legs - just watch for guys who consistently aim for one area)
* This bot locks on to dead bodies. I think I avoided it in the sample videos, but be aware that if the bot has a choice between two targets to lock on to, it chooses whatever is closest to the crosshairs, so a nearby body may cause someone using this to miss. I'm sure other bots could be programmed to ignore bodies.
* The smoothing factor described above means that if two targets are roughly the same distance away from a bot user's crosshair, but on opposite sides of the crosshair, the bot could be trying to aim for something the player isn't. Similarly to the above point, I would not be surprised to see other bots programmed to stick to one target until the aim key is depressed.

If anyone has any other tells that they would like to add, I am all ears. I want this crap caught by any admins who pay attention to their servers/leagues.

For the people who thought that video #1 was the bot, I would like to address some of the theories you had:

"in 2 you miss a lot of shots. in 1 it seems that you missed very little if at all." source

For #1 I was holding back from firing when I knew that I was in the type of scenario where I'd miss (bounced by a rocket, awkward positioning, whatever). Realistically, I probably would have switched to a different weapon if I was put in that situation in a real game.

"also in 2 he seems to lead on from the bots after they died so it appears like he was anticipating them continuing moving in the direction they were, that seems far more of a human reaction than a bot one." source

This is sort of addressed above, but the bot only makes major adjustments when my crosshair is a decent bit off, so those were indeed human reactions, but it was also the aim-assisted video.

"Definitely voted for the first one. Each trigger seems to be pinpointed on the enemy with little straying from the target. The second run looks sloppy and the aim strays from the target much more often." source

and

"Agree with the first one being the aimbot. It's very reminiscent of a console FPS lock on, there's a very consistent cone that the aim will be around a target, whereas the second video shows a lot more variation and error you'd expect to see in a human." source

In the second run I spent more time running around and getting into fights in awkward positions. For the first video I set myself up to fight in almost all battles, so my manual aim was mostly within my comfort zone of being able to track well. I also know these bots too well.