Heh, I can distinctly recall just how disappointed I was in Jessie's behaviour the very first time I saw this episode. Gotta say that she probably came off worse in this one than any other episode I can remember. I mean, the joint theft of Otoshi's badges easily rates as one of TR's meanest Kanto-based crimes, but then it wasn't exactly unexpected of them - but Jessie's betrayal of her own team mates, as James pointed out, just seemed low even by Team Rocket standards. Even her self-opinionation seemed to be pushing dramatic new heights in this one - I don't know why she'd suddenly become so mega-confident in her prospects at the Pokemon League, particularly given her track record and the fact that she only had two pokemon, one of whom hadn't seen the light of day for some time. She may have been one of my favourite characters, but I had absolutely zero sympathy for her one this one.
Otoshi certainly did well to earn all those badges, but if I'll be totally honest I really don't think that he was all that great a trainer, and it wouldn't surprise me if he got wiped out very early on in the Pokemon League. I can identify one very definite weakness in his training procedure - and that's that he'd very clearly put all his eggs into one basket with his Marowak, hence why he ran into so much difficulty when it temporarily deserted him. It was kind of obvious that he'd devoted all his time and energy to training that one pokemon whilst neglecting to train and strengthen the rest of his team. It's more-or-less safe to assume that Doduo was his second-strongest Pokemon, otherwise he probably wouldn't have used it as his Marowak-substitute...and it got its butt whopped by Jessie's Arbok, of all Pokemon! That's probably not a good omen.