I would let my 10 yr old go in the mens room if HE had to go. I would wait right outside. At least at the airport. Well, my DS is 11.
I think I understand the OP was more concerned about her DS standing out in the airport alone while SHE was in the ladies room. And there is a whole different dilemma.
Personally, in a strange, busy airport? I would probably bring my son just inside the door if I felt that worried. Many women's rooms have that entry hall way type thing. He could face the corner and hide his face, since he would be dying of embarassment. And we could do the whole "hey, you okay?" thing. That way I wouldn't have to worry about someone walking away with him or anything. Although in truth, he would probably wait right outside the door for me. If anyone grabbed my DS, he would go nuts. My older kids are both trained in self-defense and would have no qualms kicking and punching an adult who came anywhere near them and tried to do anything. I have also taught both my kids to yell FIRE, not HELP if anyone tries to grab them. People will run to see a fire, but many won't get involved if someone yells help.
At Disney, he would (and has) wait outside for me.
But that is MY son. The OP asked about hers and I cannot really say what she should do, since I dont know him.
I would be uncomfortable with a boy of that age in the ladies room, even if I knew he was in there for a good reason. Sorry, but I would. Even if I took mine into the "entry" like I said, I would feel funny about it.
And I would KILL my DH if he took my 13 yr old daughter in a men's room. As he says, "there are some things she REALLY does NOT need to see" I'd prefer he stood outside the ladies room and played open the door and yell to check.
