It's not illegal. Lawyers give political donations to Florida judges all the time. I can't speak for Grier, but if I were a judge, and some lawyer gave my political campaign $500, that would not motivate me to rule in his client's favor.
Same here. This proves nothing and it goes on ALL the time.
How could anyone besides you be sure of that? If I were an Attorney defending or prosecuting a case in your court, I would not be comfortable with the fact that you received a donation from the opposing team. I would demand a new Judge to hear the case.