Thanks for the reply. She had a paper ticket
I'm afraid the inspector will have seen this as a red flag.
Buying a paper ticket from Canary Wharf to Hayes and Harlington is very expensive. It's £10.90 single or £21.80 return. Why is she doing that? On contactless it costs less than half the price with single fares at just £5.10 in the peak, or just £3.50 off peak.
At the same time, there is no contactless to Twyford, and paper tickets only are available. £43.20 for a return.
Contactless cards need to be tapped out to calculate the fare due, so she'd need to exit the train at Hayes to pay the Hayes fare. But if she has a paper ticket, there is no need to do that, and she can just stay on the train and hope not to be caught. Twyford also has no barriers, so if you have a short ticket you can exit without issue, and that is why the revenue team will block the station from time to time.
As part of the stop they will have taken her details including her name and address. I note your location given on the forum is Twyford, which is quite a long way from Hayes and Harlington! What inferences from all of this information might the revenue team draw about where your wife usually begins and ends her journey?
TfL may audit your wife's ticket purchasing account if she has been buying her paper tickets online to discover if there are further offences.
Some important questions to consider:
Does she often buy her tickets to start/end at Hayes and Harlington?
Does she travel every day/most days/for work?
Does she have any evidence to support her story that she leaves the station at Hayes and Harlington?
TfL will write to her in due course and ask her for her side of the story. They take a dim view of ticketing matters like this, and often prosecute the offences, but sometimes they can be convinced to settle out of court for the fare/s avoided plus an admin fee. It is best to wait for the letter first, though.