No, he promised to pay a certain amount into an established scheme. Then he did so. He's upheld his side of every agreement he's been party to.
> Then, he put his money in a pension scheme that actually wasn't charging enough.
Enough for what?
> Now, years later, once some sane accounting rules are put in place, it turns out that there isn't enough money to live up to the promises that were made.
What promises? Why do you think they can't be met?
> It sucks that a decision like this would make a business go bankrupt
There is no business involved here any more. It's just an individual person who once employed people.
> but that's what happens when you make financial commitments that you can't afford to pay
He didn't make any such commitments. They were conjured out of the air by a legal change that rewrote the terms of his pension contributions retroactively.