That looks like where this is headed. I am going to call them again tomorrow and see how it goes
The police are probably going to say it is now a civil matter to be decided in court. They also suck at giving legal advice. Your state might have an attorney referral service and many of those guys will give you 5-10 min. free consult on the phone.
When you talk to the body shop guys, you can mention (bluff) that you have video of the bike being stolen, right before you demand that they cut the crap 'cause you know it was one of their guys. If they ask to see it say your attorney has it.
AFAIK contract law requires consideration and execution, none of which have taken place yet. Unless your state or municipality grants special rights to body shops/mechanics they really don't have anything.
Let us know how it goes, and good luck.