Declassifying first class when large number of seats available on train

[TUC]

I was intrigued by a letter in today's Telegraph as follows:

'SIR – I boarded the 7.48am train from Rochester to Cannon Street on Monday and settled into a first-class seat. Within two minutes, the conductor declassified first class.

There were 176 empty seats on the train.'

Would this actually happen and, if so, for what reasons?

 

[AlterEgo]

Someone bought a first class ticket on Southeastern you mean? First time for everything.

 

[Haywain]

There were 176 empty seats on the train.'

Really? Did they walk through the train and count them?

 

[Bletchleyite]

Some guards seem to do it on LNR if the back of a 12 car is full and standing even if the front is nearly empty.

 

[Graham H]

Had the same on a southern service. I was in coach 7 of 8 on a Portsmouth to Victoria train. After Gatwick guard announced declassified 1st yet there were plenty of seats where I was and a quick headcount showed only about 25% of seats were occupied. I can only assume front was crowded with Gatwick boarders who hadnt bothered to move down the platform.

 

[TUC]

Really? Did they walk through the train and count them?

I assumed it may be a seating app which shows you how many seats are free?