Given that nobody else "noticed" this incident maybe the OP should tell us more?
The OP's summary pretty well said it all. The report of smoke (in the rear of the passenger cabin, it seems) must have been during or just after takeoff, because the aircraft made an immediate right turnout onto a downwind leg and subseqently landed on 09R, squawking 7700, after less than 15 minutes airborne.
Given that, as BOAC has helpfully pointed out, the incident must have been apparent to anyone who was monitoring departures at the time, or indeed the world and his wife looking at WebTrak in retrospect, why it didn't make AvHerald is one of life's mysteries that will doubtless never be explained.