After reading all the previous comments I'd have to say the guy you were playing is a jerk. If he's a jerk then give him a taste of his own medicine. Truth is over the last year I have become a bit of a rules bandit myself, insisting that the rules be followed 100% and I used to be such nice guy and I have been trying recently to get back to the way I was because while being a rules bandit was helping me to win it certainly wasn't making my gaming more fun, in fact it was the reverse.
After a bit of reflection and asking myself why I became this way I would have to say it was because of another of our gaming groups players and one that I regularly play. I used to let him off with lots of little things and then when I made a small mistake if it was one he could seriously capitalise on then he would penalise me for it just because he wanted to beat me, he's very easy going against other people. Even when I let him off with one of his terminators having 1/5 of its base off the table after he scattered in the same game he wouldn't let me cast my psychic powers because I had moved a couple of wave serpents before remembering.
So Slowly but surely I began to get strict on the rules when playing him but eventually it became habit and dominated my playing style. I am making a conscious effort to change my bad habit, if I was in a tournament I would certainly adopt the same attitude and enforce the rules 100% but really if your just having a relaxing game with your mates then let the little things slide. But of course so long as he keeps it friendly I will endervour to do the same but if he takes advantage when I was generous to him then he will have no mercy!