Thank you RJ, simply all I wanted was to know this chap was an RPI. While I understand using a bank card instead of an Oyster (and in this case it is just one less thing for me to misplace, and it is easier for me to track spending) attracts risk, I think this is probably easier for the railway because it is cheaper?
There was a metal badge and wallet. Thank you for posting a link to this PDF it was very helpful. In particular"
8 Written Instructions to Authorised Collectors 8.1 Authorised Collectors will wear a distinctive uniform that clearly shows that they work for GTR, along with an indication of the route they normally work. In line with rule 5, they will carry identification and produce it when charging a penalty fare or when asked by a passenger. This identification will include the Authorised Collector’s photograph and will show that they are authorised to collect Penalty Fares on our behalf and on behalf of any other operators who have authorised them to collect penalty fares. We will not allow Authorised Collectors to collect Penalty Fares if they do not have this identification badge with them. The design of this badge will be in line with the code of practice on Penalty Fares produced by the Association of Train Operating Companies, and an example is shown in appendix F.
I can report that I got on the same train this morning, I stood in the rearmost carriage (just outside 1st class, which was probably declassified... A term I have picked up from reading this forum lots over the last few days), the RPI got on at the stop after mine and left one stop later. No tickets were checked.
I did not start out wanting to cause an issue or to complain, but I now have and I have taken all your comments on board. Normally I do not have any issues with Thameslink staff (Southern is another issue), and I hate complaining but in this case I feel that I was reasonable and the staff member was not.