We don't know that George Osborne hadn't been in standard on the trip up and wouldn't have been so had he got the intended train with the seat reservations in standard, so this nonsense about standard 'being beneath him' or even the aide saying he couldn't possibly sit in standard (in front of other passengers, which would be a pretty dumb thing to say unless deliberately wanting to cause a storm) seems like nothing more than that; nonsense.
I can perhaps believe the aide asked the guard/TM if he could sit in first class as they had no seat reservations on this train (As Flamingo says, I am sure people ask every day for various reasons - and in some cases, they might be allowed and for others, they're not). I can even imagine her saying he couldn't sit in standard, on account of there being no room (or a table seat that they wanted to actually work - and not merely kick back watching a film or something). I just don't imagine the aide would be silly enough to say anything to get him, or the entire party, in trouble - at least if the aide wanted to keep their job.
Perhaps the journalist misheard, or deliberately twisted what was said? I can also accept that someone might not realise how much it costs to upgrade and could argue about the cost, even if they then go ahead and pay. I doubt staff see that as being abusive; I know I've gasped and said 'how much?' when buying a train ticket and being shocked at the price. It's not an arrestable offence!
The fact is, in any case, it wasn't George Osborne who said anything about not wanting to be in standard (or not being able to be in standard because all people in standard are scum and should kneel down and worship the ground he walks on) and the train staff have said there was no argument.
It means that while SS4 has been attacking the Tories for as long as I can remember, this isn't anything to use against the party. Nor, for that matter, is it worth attacking members of other parties for the same thing. The video showing that Ed Miliband did the same, even removing the antimacassars for the cameras, is probably why Labour should keep quiet - especially after the revelation that significantly more Labour MPs use first than Tories.
However, even though it's 'my money' I would not argue with MPs travelling in first class when working. They don't need to do so when commuting to/from work, so a first class season ticket I wouldn't agree with. Given their salaries, I am not going to worry about a few hundred quid here and there for them to be productive while travelling.