With regards to somebody trying it on, I would be very surprised if they could actually be bothered to go through all the hassle of doing so! I've only had to use the taxi option a handful of times over the years, and it always seems quite difficult to firstly hunt the supervisor of the relevant TOC down, they then have to book a taxi for you and then you have to wait for said taxi to actually turn up, instead of getting home for 11 last night it was closer to midnight!
A month or so from now I would have been fine with the extra 23:00 and 23:16 services from Leeds!
Firstly I am glad you were able to sort something out, I know what it is like to find yourself stranded at somewhere like Leeds. Back in 2007 I was on my commute home to South Elmsall where I then lived during the evening peak. Unfortunately this particular evening was at the start of the dreadful floods that hit a lot of the area and on arrival at Leeds (commuting from Bradford) I was greeted with the ensuing chaos as most trains heading south were cancelled. So I sought out a member of Northern staff for advice, and they informed me that there would be no trains to South Elmsall and that as a Metrocard holder it would be unlikely that alternative transport could be arranged, as bus companies were unable to be booked due to the weather and taxi options were only be used for passengers with no other means of getting home. And as I had a multi-modal ticket, they advised that I head for the bus station to get a bus home.
So this is what I did, waited with hundreds of other people for a 110, which as it turned out would be one of the last to run, and head into Wakefield. However once I got there all buses south had also stopped running, and so I had no option but to convince a taxi driver that I could help navigate a route home, which by a very convoluted route I did. But in total it took over 6 hours from work to home & left me £45 lighter, which is why I now always have a plan B and the moment things appear to be going wrong I am exploring other options. Its the best advice I can give anyone.
As for people trying it on, I'm afraid I disagree. There will always be people that would do so, even if they had to hunt the supervisor down. Some people will do almost anything to get something for free, and some will even just do things like that because they can. Thats just how some people are sadly.