Incidentally this is the first time I have witnessed a reader in use on any of the TOCs that serve Watford.
Don't use LO much then?
I've had my Oyster inspected with a reader several times on London Midland (not yet travelled on WMT), though a long way back before they got readers, just presenting an Oyster was sufficient.
I could be wrong and maybe they arrived on an earlier train and did touch out.
If they touched out at WFJ, they should have then bought a ticket for the non-Oyster journey.
While I have seen passengers touching out but not going through the gates and turning around to go back to the platform, I assume they already have a ticket for the next part of their journey, though at some stations their behaviour seems to indicate that they are evading the correct fare (their destination probably has no barriers so they touch out ASAP after touching in to pay a lower fare, then travel ticketless through extra zones).
Can the reader see a season ticket ? If anything this makes it worse as it implies the passenger often traveled beyond Watford without a ticket.
I believe it does show travelcards. My understanding is that strictly speaking the passenger should have sought out the guard before arriving at Watford. An RPI could have caught them out.
The guard implied there was some software system link between the reader and the ticketing machine - so the machine wouldn't work unless the Oyster was scanned - that's a spoof isn't it ?
Seems dubious to me, perhaps the guard just meant that his company requires him to inspect Oysters before selling tickets where the passenger claims that part of their journey is covered by Oyster.
The guard's machine would surely need to work in a situation where the WFJ ticket office is closed, ticket machines are not working and barriers are open.
My question to anyone reading is - I thought the Oyster handheld readers record their current location, so that contactless cards can be charged with the correct maximum fares if the user has not touched in or out appropriately. How would this work if inspection of a CPC takes place outside the Oyster area?