I think you misunderstand how contactless and revenue inspections work.Sorry, I don't really understand this.
I thought if someone didn't have a valid ticket and couldn't give a good reason for this, then a penalty fare was issued.
The inspector didn't tell them that the phone / card would be blocked for future.
I'm not sure what 'validated' means, is it just that it showed they had means to pay?
All that happens during the revenue check is the card is touched on the revenue inspection device. The inspector cannot see whether or not the card has been touched in at the start of the journey.
The reconciliation happens overnight in the back office. There are two possible outcomes:
1. The card was touched-in (or validated to use the technical term) before the revenue inspection. If this happens then the revenue inspection is passed.
2. The card wasn't touched-in before the revenue inspection. If this happens the revenue inspection is failed and a maximum fare is charged. The card is blocked from future use on the TfL network
Based on what you've told us these girls will be getting charged maximum fares.

