OK - if you were referring to the evening LGW-IOM-LGW, then, I agree that time-keeping is poor, and it is particularly accentuated when the scheduled arrival is so late anyway.
I do just need to correct your recollection regarding BA's involvement with IOM-LCY. Yes, there was a previous incarnation on the route, several years ago, (it is too late to look up the exact dates!) but this was withdrawn entirely and only re-instated when the financial incentives were made available through local (IOM) business connections.