Sure, that is a possibility and if it is what happened, as others mentioned, if the op tries to go to Court, BA may well be able to demonstrate they had a reasonable excuse to do what they did. Indeed, I myself precisely said so earlier on (where I pointed out that if the suspicion resulted from information from an authoritative third party - such as the police - this could create reasonable excuse - see post 57).

However, I daresay that it is vastly more likely that BA's actions proceeded from their own processes and quite likely from more generic causes of suspicion, in which case I do not believe there would be any such excuse.

None of us can double guess those things short of some unreasonable levels of speculation. The person best placed to know if something problematic is likely is the OP him/herself. If, they are aware of potential issues, I'm sure they would not start a legal case, but if instead, as I would certainly assume based on their own description of events, their situation is strong, then again, I would expect them to have a strong chance to be able to recoup expenses related to BA's breaching their contract if they choose to pursue this after seeking competent legal advice. In the unlikely case BA were indeed tipped by the police or equivalent on the basis of the suspicion of something sinister, BA will have to demonstrate this and the OP can then figure out what happens next.