Really there are two levels of AI capabilities here. One that we already have and is causing tons of problems, and a theoretical one that is very likely to exist soon.

If we are lucky AI will attack some billionaire like you say and people will be held liable.

If we are not lucky people will not be held liable and labs and the military will keep pushing the limits until a sovereign AI gets loose and then have a fucking mess where AI takes itself out of the human control loop.