Devil's advocate maybe but.. I'm not sure but I think once you've sneaked through the barrier then things change a bit as you could be said to have actively avoided trying to pay a fare, indeed you didn't even try at the London Bridge end at least. This as opposed to not having had chance to do so, hence it's questionable how relevant the article is, and how relevant Ramble66's example is which specifically states they hadn't even tried to go past the barriers. The OP on the other hand failed to buy a ticket twice then actively found a way past the barrier without paying, whatever the intentions were on the other side. As for suggesting a position the officer has already done that for you I'd suggest. Be very very sorry, tell them what he told them to tell you, and cross your fingers.