Yes Illinois. Yes licensed and insured. Yes permits pulled but city has no evidence of inspection. I only noticed this because I was replacing one of the bathroom fans and needed to climb into the attic to do it. That's when I noticed the mold and the vents just stapled to the rafters I'm sure after they were disconnected from the vent in order to removed the sheeting.
In Illinois, there is a 5 year statute of limitations on filing a property damage claim, so you might have difficulty holding the contractor liable 8 years after the fact.
Here is a link to the law:
http://www.ilga.gov/legislation/ilcs/documents/073500050K13-205.htm
That said, there is a "discovery rule" which can in some circumstances extend the statute of limitations from the time the damage occurred to the time the damage was discovered (or reasonably should have been discovered).
You can discuss this with an attorney in your area to see if pursuing a legal action at this time is possible or, if possible, prudent.
You might want to get estimates (3 are best) to determine the possible costs of mold remediation and balance these costs against the cost of (what could be futile) litigation.
Good luck.