How could this happen...

My boyfriend took his flight back home yesterday, from Montreal's airport. He was supposed to arrive in London around 9AM GMT and depart at 10:55AM to go to Manchester.. They forgot him in London. Since he's in a wheelchair, he could only look at the screen and see his flight depart without being able to do anything.

This isn't British Airways' fault, but the airport's staff's, and BA strongly suggested to make a complaint.

Don't worry, they'll hear about it.