Perhaps the pax didn't leave their seats till the train stopped like many people do then wonder why the train leaves without them.
I've recently ridden on some Derby buses and I've noticed that no one gets up until the bus has stopped.
I dont know if there's been some safety campaign (I dont read the Derby paper) or whetrher it is the case with other bus companies.
Maybe the pax are applying the same principle on a train?
Having said that until someone appears at a door the TM, being on the p[latform, does not know they are there.
Something similar happened to my daughter the other Saturday.
The train arrived at Belper. A bloke was leaving by the front door of a 158,. Behind him was a woman with a push chair, behind her my daughter.
The bloke alighted but the woman got her push chair stuck, trapping herself and my daughter. The guard, being at the rear on the platform, saw none of this, closed the doors and gave the right away.
The next stop was Ambergate and, they having phoned for a taxi, he gave them a fiver for the trip back to Belper.
Well done EMT.