I'm not so sure Pikachu even had an excuse with Snivy. Despite not having electricity, it still had Quick Attack and Iron Tail to work with. Honestly a single Quick Attack should've been enough to end the match, unless Juniper feeds her Pokemon nothing but steroids or something.
Eh, I think Pikachu was weakened across the board by that thing, it wasn't just attacks. And besides, if you find out you can't use certain attacks that'll mess with your...focus and whatever, which could have left him open and stuff.
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http://img.imgcake.com/Xiiijpgen.jpg - Me, as drawn by Ayvuir (who is also a giant douche)