Go to the back cab and knock on the door!
Thats probably the first place I would look for them.
Or when he says he looked for the guard what he actually means is he sat down and waited for the guard to get to them, IE made no attempt to actually find the guard.
I reckon that an ordinary member of the public, with no specialist rail knowledge, would fear that knocking on the cab door is "not allowed" and/or distracting a guard from a safety-critical duty.
When I first started travelling by rail regularly, I once waited for two hours, on a weekend train, for a FGW staff member to come through the first class carriage to check my standard class ticket and take my flat £10 weekend first upgrade (as it was then). I considered knocking on the cab door, but decided against it for the reason stated above; in the event, I was eventually able to pay the £10 on board the train.
Subsequently, I once travelled directly from Patchway to Reading (via Bristol Temple Meads) on a pre-purchased first class advance ticket, which I had previously collected from the nearby Bristol Parkway station, and didn't have my (valid) ticket checked at all during the c. 2 hour journey.
It raises the related question of whether, and to what extent, a passenger, who has boarded at a station with no purchase facilities, is obliged to actively seek out a guard on board the train, even to the point of running up and down a (crowded?) eight-carriage HST. This, and the 'requirement to delay's one's journey to purchase at an interchange station' when delayed' are both matters I would like to see clarified, either as part of a PF review, or otherwise.
At present, the uncertainty surrounding the interpretation of the law means that TOCs can, in practice, extract large sums of money from passengers in this position by threatening them with prosecution, in the knowledge that the passenger will likely not want to take the risk of conviction.
