Forcing a disability retirement, not illegal.

Forcing disabled police officer into a disability retirement did not violate Michigan's disability laws...

Even though plaintiff-police officer had a permanent heart condition and worked a desk job, defendant-city did not violate disability laws when it forced him into a disability retirement after determining that plaintiff’s condition prevented him from performing physically demanding activities contained in an “essential functions list” that defendant deemed all officers should be able to do.

The case is: Penden v. City of Detroit.
Here is a link for a copy of the case: http://courts.michigan.gov/supremecourt/Clerk/Opinions-03-04-Term/119408.pdf