Last year flying Air Asia in KL...upon exiting the gate there were 4 or 5 planes on the Tarmac boarding at the same time... With all of us exiting through the same gate at the same time it was utter chaos. Lost outside an Air Asia rep looked at our boarding pass and pointed us towards a plane.... The wrong plane. One heading to Manilla instead of Denpasar. Luckily we clued in when we found all of our assigned seat numbers were occupied, and found our way to our plane.

So it totally CAN happen!