Noah and the Elderly Gentleman

Last night was ECA's homecoming and the place was absolutely packed.  Every seat in the house was taken.  Baylee, a cheerleader, had a big halftime dance to perform and I was anxiously awaiting seeing her being tossed up in the air and caught.  So here we are, sitting in the bleachers, and Alan was between Noah and I.  Noah had his IPOD touch with him so he could keep himself occupied for the 4 hours we were there. 
I noticed an elderly gentleman, probably somebody's grandpa, take the seat next to Noah.  Right next to Noah.  I didn't really pay much attention to what was going on because the game was pretty exciting and I was watching Baylee as well.  When I glanced over a few minutes later, this man was trying to talk to Noah and he had his hand on Noah's leg.  Alarm's went off because I knew that Noah was very uncomfortable with this senario.  His body was contorted in my direction as if that man was like scalding water. 
Noah can't say hello to someone he doesn't know, much less strike up a conversation with them.  Autism is a social disorder.  And I don't even want to talk about touch.  Noah needs his personal space.  There are a few people that he will let hug him and and that includes us and other family members.  I'm pretty sure that Noah was about ready to lose it when his leg was invaded. 
I was thinking to myself that this man probably thought that Noah was being rude.  I contemplated explaining the situation to him but with the noise level in the gym, I didn't bother.  I can't always explain to others why Noah is the way he is.  I do, however, need to teach my son to respond to people the best he can.
I do want to say this.  Noah isn't shy.  Anyone who knows him gets that.  And it does drive me insane when people try to talk to him and he doesn't respond in the manner they think he should, we get,"Aww, he's shy."  No, he has autism.  He doesn't do it on purpose.  To say hello to someone and to actually look them in the eye while doing so is actually torture for him.  He want's to engage in conversation, he just has to get over that initial fear.
We are taking baby steps in Noah's conversation skills.  We might make a goal for him to say hello when someone says hello.  Sometimes we ask him to say hello first.  This will be a lifelong struggle for him but I have all the confidence in my God that Noah will prevail.