It is not appropriate to level a "penalty" in this case, but the maximum charge they can make under certain circumstances is to charge a full Anytime Single fare.
You are entitled to this opinion, but I am entitled to the opinion that it is ridiculous.
This is incorrect. The correct action is to charge the lowest priced fare that would have been valid, which - depending on the train caught - is likely to be the 1st Off Peak Single @ £120 http://www.brfares.com/#faredetail?orig=EUS&dest=LIV&grpo=1072&grpd=0435&tkt=FSS
The company is not permitted to "fine" people and is not permitted to charge the Anytime fare if the Off Peak is valid. However not all their Guards act correctly, so I would be very interested to learn what train he caught.
Even Virgin's own policy online says that you should be charged the fare that would have applied if you bought the ticket at the ticket office, which would have been an off-peak. The selling of Anytime tickets only applies if you travel without a ticket at all, so I suspect this passenger has a good chance of getting money back and an apology.
"If you travel with an Advance ticket on the
correct date, but on the wrong train, you will
have to buy a new ticket at the price it would
have cost you from your starting station. You
may be able to get a discount if the Advance
ticket was purchased with a valid Railcard."
https://www.google.co.uk/url?sa=t&s...tB5MQFghNMAI&usg=AOvVaw0FUV86BtYFKI6JA3v6ro5J