I don't think anyone is saying this one mistake is what makes Betts a potential bust. The mistake combined with him being unable to get meaningful minutes on a bad team in his 3rd year of college basketball is why he is potentially a bust, at least as far as this level is concerned.
Obviously players make mistakes....Chris Webber is certainly an example of that but that is where the similarities stop because Chris Webber was also a phenomenal basketball player who went on to have a 15 year NBA career.
I'm never one to give up quickly on players. Betts is still on the younger side, maybe it clicks for him eventually. But he looks like someone that would benefit greatly from a drop in competition level and a change of scenery.