Well, I think it is a fantastic idea in principle, which I support.
Giving money to help children at Christmas who may not be in as fortunate a position as others.
But everything you then add on to the initial principle, politicises it as others have mentioned. It would be reasonable to presume, from my position as a working union member, that the person collecting the donations, would be thoroughly aware, not to knowingly rub anybodies nose in it. I mean, the collection is for sacked and suspended crews families, which would mean you would be lighting up all the anti BASSA radar's. I imagine the employee in question acted in good faith and the intention was in line with the general principle, but unfortunately the employer will be the judge, jury and executioner of the situation.
As to the complaint, that is the world we live in when you have two sides to a dispute. If anything more happens to the employee (if it turns out that they were just walking though the workplace with cap in hand, a happy smile and kind words), other than ask permission next time, then the reasonable person might just turn against the employer, for the first time in a while.