It's not BS, the guy used rubber style, so he implied non conducting nature of rubber to as lightening as weak it. As for 3rd raikage cutting that rubber ball could be simply due to him using stronger lightning attack, while clearly sasuke didn't aim to kill the other guy, so he probably used a weaker attack.
OT: The episode was cool. The Fuushin guy looks weird but then SP filler characters usually look a tad like they don't belong. It was still cool though.