Hmm yes the 'bmi best off blocks time', Air uk/KLMuk were notorious for this during my time as a dispatcher at Aberdeen, they were forever on the phone after the flight had departed arguing with dispatch as to who they could blame for the delay. If I remember right they used a table of delay codes that blamed various companies/reasons and invariably ATC would get it. It was never the fault of the Airline or the ground staff messing up the check in figures etc...
Richard, I bet you remember this well!
Bmi can push back from the gate and hold for 30mins and it's all the fault of ATC.