Is this Legal?

A friend of mine was arrested today on a warrant for driving with a suspended liscecse. A local police officer said he seen my friend driving a car on 4/03/02 and just today the warrant was executed. First of all, my friend has never driven said vehicle (or) any other since the beginning of his suspension. My question is...
Can a law enforcement official do this? At the time said police officer said he saw my friend driving; he or noone executed a traffic stop. This seems somewhat peculiar. At this time my friend sits behind bars an innoscent man arrested for a traffic offense he did not commit. What can he do; and what legal rights does he have. We reside in Kincheloe, Michigan. Chippewa county.

Thankyou,

Your friend should be able to get out by posting bail. Ask.
Your friend should ask for a copy of his driving record. Or where to get it.
Your friend should plead not guilty when he goes to court.
Your friend may want to speak to some compitant adult to prepare his defense to charge.
The prosecutor will have to prove that the charge is accurate at the time of arrest. And you said he wasen't driving.
The same thing happened to my son last night and I had to post a 500$ bond to keep him from being taken to jail. In this age of computers your record can easily get messed up because information is only as good as the person who enters it.