Wondering if I can get people's opinion here please.

My brother-in-law needed to change his flight today and actually forgot to change it until it was very late. He called to change his flight 20 mins before departure but got stuck in the BA call centre queue for 25 mins and therefore by the time he was able to speak with an agent he was unable to change his flight as it was already past departure time so he was considered a no show and now has to buy a brand new (one way) ticket back to UK

Somebody suggested to us that because he had to wait in the call centre queue for so long BA should be a bit lenient here and allow him to change his flight as originally planned instead of having to buy a brand new one and that we should complain to BA etc etc etc.

My honest opinion here is "you left it too late, you have to deal with it now" but I just want to see if I am being too harsh here and whether we would have a chance of getting the original booking reinstated to a later date (incurring the change fee & fare difference etc)?

Thanks in advance!