Maybe it’s possible that he suffered a bit of neurological damage from the infection? My first bunny, Tammo, would have seizures but they were more protracted, always preceded by very stereotyped movements, and followed by exhaustion. However, we never got a good answer from the vet regarding what was wrong with him. I think this absolutely should be evaluated when possible, but as long as these episodes aren’t progressively longer or increasing in frequency, it’s not something you need to make emergency plans for (as long as you don’t hold out too long either).
I understand it’s easier and cheaper for your dad to see your bunny for the occasional checkup. However, rabbits are great at hiding serious illnesses and often present very acutely. I encourage you to at least be familiar with local vets in the case that an emergency situation should arise and a 2.5-hour drive to Houston might be too much stress for him. Not saying this is the case right now, but just precautions
.