We should know by now the anime is not perfect when it comes to typing and stuff.Well according to the anime they are not! Just watched the epsiode and both Gligar and Gliscor both got hurt by electrical attacks!
I will give Thunder Punch a chance however, as it still involves punching the pokemon, but thunderbolt should not have hurt Gliscor! OH WELL!
I wonder if they will keep the Gligar, falling out of the sky and onto Ash joke?