I'm not sure this would be a B.S. termination. The company will probably want to set an example here. If they don't, they may run the risk of others having the attitude that the rule is not strictly enforeced.

Corporate image is huge here too. Public perception is key and it would be easier to put all the blame on this guy then terminate him than to deal with the consequences of trying to do the right thing.
I would hate to see anyone lose thier job, but when it comes to alcohol and flying, there usually isn't much forgiveness.

I just hope this guy is given the option to resign, then at least he will still have a career and a clean record.

I don't think a union could save the day either. I saw guys get let go for busting the 12 hour rule at my former company. Similar situation in that they didn't break the F.A.R.'s (8 hour) but they did break company policy which was zero tollerance. They were given the option to resign and took it.