I'd have been very annoyed if I were the OP. At the risk of sounding very DYKWIA they should target non-status pax first. It's not only BA though, at T4 I was recently told by KLM staff that I had to check my bag in as it was a "very small plane", which is rubbish as it was operated by a 738. Her colleagues had already collared various passengers. I told her my bag fitted under the seat in front (which it did) and that I would put it there (which I did), it it was noticeable that there was plenty of space in the overhead lockers around me. My experiences on BA have been better, but it would help if people didn't take on ridiculously sized trolleys.