Hmm, I think it might be easier to think up more of these once I've had a go at the game itself, but I'll try to think up a few anyway.
Locked Direction: Every turn that the bot actually moves, it has a chance of getting temporarily "locked" into the direction it is moving; for the next 5 turns, it keeps moving in that direction no matter what. Obviously this means them smacking into walls and such. You could put this one on a bulky sort of enemy, at which point it can also shove other bots out of the way when it locks up like this. Their speed does not increase during this, they just keep walking on forward.
Ultimate Shield: This one would be for a bot that is capable of putting up a shield or forcefield around itself & allies, if there is one. When it goes to use this ability, there would be a chance that instead of a normal shield (which just increases defense or whatever) it instead puts up an "ultimate" shield, which gives a massive defense boost.... but the bot in question can now not fire their weapons back OUT of the shield, essentially locking them out of the fight for a time, though they could still move.
Glitched Nano-Repair: Some bot normally has the ability to repair/heal teammates for a certain amount, right, well this glitch would occasionally reverse the heal, damaging them for that amount instead.
Rocket Misfire: A bot firing a rocket or whatever could have a chance of the rocket not quite coming entirely out of the gun, thus simply exploding right there, destroying the gun entirely and damaging the bot that was holding it (and others around him). If the rocket launcher was the only weapon the bot had, it could perhaps then choose to simply try ramming the player's bots, or could just walk around all derpy and confused.
Booster Overload: Bot that normally has some sort of temporary speed-boosting or "rushing" ability could occaisionally "overcharge" that ability; causing them to launch forward twice as fast/far, with a high chance of ending up at a different spot than intended, and if they hit something while doing this, they hit it HARD, doing big damage to themselves and whatever they hit, including the player's bots of course.
Too Tall: A very large (and probably very stupid) bot could be very darn strong, but unable to target things that are beneath a certain size. If you have large/heavy guys on your team, it'd come straight at them, but otherwise it'd get a bit confused, flailing in random directions if something small is attacking it.
Super Sight: Bot can see through walls/objects/whatever, perhaps alert other bots to targets behind those walls. As a trade-off though, the bot forgets the walls are even there. Hilarity ensues.
Berserker: This type of bug could apply to a dangerous, high-damage sort of bot. Initially, it wouldnt do very much, patrolling around looking for targets. When it sees the player's bots, it rushes forward, entering a berserker rage as it goes. It never stops fighting after this. If the player's bots leave the thing's line of sight, it just keeps going bonkers, charging at any valid target and pummelling them until it runs out of things to hit, at which point it would run around the area like a maniac, looking for more bots to clobber, occaisionally punching walls and things for the heck of it. It could also enter rage mode if another bot inadvertently shoots it or something.
Heavy Metal: This bot can rip metal plating off of the walls, or pick up pieces of other bots, and attach them to itself, giving it a permanent defense increase. But it's not very bright and doesnt understand the concept of weight; each time it does this it's movement speed/ability/whatever drops, until eventually it's so plated that it cannot move or even turn around.