There are anumber of things that could of happened, not being the snipper.
1) Someone could have ratted on him for "being the snipper". He could own a .223 rifle. Someone that doesn't like him and can provide some details could make this guys live pretty bad. It is possible he had nothing to do with the snipper, but is believed to have illegal firearms.
This would jive with him being asleep at a rest stop. It is possible he was asleep when the alert was issued and woke up to a very nasty suprise.
2) I heard/read the kids fingerprint was found at montgomery alabama in a shooting that involved a .223 round.
http://215stop.com/
It is possible that someone in Alabama knew the round was a 223 and called the police pretending that both are related.
However, none of this seems to fit the MO of the snipper(s). But you never know...