This is not some banana republic where such things happen with the major based operators, which you maybe have experience of elsewhere.
"Cough, cough" Spain "cough"
We were lined up no 3, and at the two LINKS, two BA's departed before us; when everyone knew it the next to leave was us.
If you're a heavy and they weren't then perhaps it was for flow management. Perhaps they had slots and you were early. Perhaps it was mere coincidence. There is a reason why the word exists!
Don't go to a Spanish airport! You'll top yourself! (Unless you are flying for a Spanish airline).