A quick sim shows that it breaks quite quickly since the probability of the anticanni mechanism breaking far exceeds the probability of an actual cannibot arising. There's not enough need for it.
I thought of using a bot that randomly converted to canni a few percent of the time, but since cannibotism is disadvantageous in an environment of anticannis I'd expect the cannibot-inducing gene to break.
If poison affected conspecs then that could be used rather than the clumsy counterattack gene, but after modifying the code to do just that a while back I found that poison was too unforgiving - a stray shot could brush an anticanni and it would poison the 'attacker'. Then the resulting melee would result in more bots getting tagged, and it got messy pretty quickly.
A tiefeeder might have better luck, since a bot can instantaneously and precisely leech from the offending tie. Perhaps a second population of hostile tiefeeders could keep the leech gene unbroken, and then cannibots would be disadvantageous since their conspecs would simply be far too defended. Might even see the two populations evolving measures to prevent them attacking each other.