I just saw a minor bug involving transform and batton pass. First, the oponent Smeagle used trasform on my Espeon, and then used Batton pass (Being transformed on Espeon). When he switched his Gengar, the sprite of Smeagle was shown ovelayed with the Gengar's sprite. This persisted even when he switched out again. It only stopped whe he switched his Smeagle again.
Sorry, but I don't have a screenshoot