I don't like the trade at all, but I do not think that a veto is in order. I am of the mind that people should be allowed to manage their team. If you found cheating then fine, but to say one person is getting way more than another, it's up on the team owners to make their own trades.
I know there are people out there saying that all trades must be fair and by allowing the trade you are destroying the league, hey that's baseball. There are always bad trades in baseball and there will always be bad trades in fantasy baseball.
In my league, there have been two vetos in nine years of the league. Teams are allowed to do what they want and the owners are generally pretty good about knowing what's going on. But there have been some questionable trades and in the end it always works it self out. We have a keeper league with salaries, so that does come into play, especially when someone is playing for next year.
But in this case, horrible trade, I would never do it, but you have to let people make their deals. When I first started, I made some questionable deals and learned from them.