Just a note this was found using an updated client so isn't this and that I tested this with a friend and got the same result again. Basically the bug is po moving for itself after you have reconnected to a battle if you cancel a switch then re-make the switch. Steps to what exactly happens. Player A chooses to switch to another pokemon. Player A disconnects. Player A reconnects, cancels the switch and then re-makes the same switch. Player B attacks and the switch would happen as it normally would. If Player B then attacks again PO automatically switches back to the original pokemon out. Seen as this can't be shown without video, no screenshots. Not a major bug, but a bug nonetheless.
[video=youtube;CE6ZhlOiueI]http://www.youtube.com/watch?v=CE6ZhlOiueI&feature=youtube_gdata_player[/video] Here's video