Tough one but at a guess the chain could of jumped we've seen a few (I'm the service manager for A1BN
www.a1bnspecialist.co.uk/ ) plus of course there will also be the problem re chain guides on top as these are a known weak point and it'll show as an error re timing as your research on the net has proven.
Always best to get it checked but checked by someone that knows the product hence a decent BMW Indy.