Here's a replay from a game I just played (I did remarkably well btw, must be because I'm ace).
1) T4 North Belfast Wallbreakers warp a player into to teleport #3. He doesn't appear.
2) T4 Elements of Discord stand up a Wood Elf catcher next to the empty teleporter pad and fail a dodge when moving away - 3) so there *was* someone on the teleporter, they just could not be seen
Later in game I think the teleporter was triggered, the invisible player shifted to another one and everyone was finally visible