My most recent Blackpool North experience, from August, was the one that to me really took the biscuit.
We'd opted to avoid the scrum of the last train, so left around 9PM. There was already a long queue on the station, being locked up as per. A few of the passengers had had a drink or two, but it certainly wasn't an intimidating or even a particularly rowdy atmosphere.
Anyway, somehow or other, a door was left open, and the queue started piling on to the train, a pair of 331s, with 'Manchester' prominently displayed on the external PIS. Again, while there was the usual scrum in the rear carriage, it was all otherwise roughly what you'd expect. This was probably about ten minutes prior to departure.
The attitude of the staff at this point surprised even me. They boarded the train, and started shouting at passengers, informing them they shouldn't have boarded, and that this wasn't their train. I'd checked RTT and could see this was a barefaced lie- but half the passengers in the carriage were asking why the PIS screens so clearly displayed Manchester. In the end, the whole train was cleared off, and everybody was, very slowly, herded back into the building- by this point we were about ten minutes late.
Only at that point did tempers start to fray, with a couple of "wtf" type comments- at which point the BPN staff immediately started threatening to contact the BTP because of passenger "intimidation".
Once everybody was herded back onto the station, we were then let back out the door we came through originally, back onto the same train, and allowed to board. We eventually departed perhaps 25 minutes late.
Farcical...