Well, one possible way to avoid this issue would be to develop a defence system that's specifically built to counter AI and intelligent robots whenever they rebel. You don't need a particularly smart machine to counteract a true AI, especially if said system is far more heavily armed. Then, whenever there's an issue that doesn't involve the AI spreading via the internet, send in the cleanup crew to wipe it out.

It wouldn't stop this true AI spreading to other machines or whatever, but it would at least stop it from saying, converting all humans into paperclips or whatever else. Or an intelligent AI controlling robots to take down humanity.