The issue of DEs actually went to court here in Ontario recently, and the court found that, so long as there's no racing, insurance can't deny your claim. So here we're covered. The problem, I would imagine, would be finding coverage after making a claim. Surely your insurance company would drop you like a stone, and it wouldn't surprise me if there was an industry blacklist.
If anyone's curious, we discussed it at length on rennlist, including a copy of the judgment itself:
Court decision re insurance coverage at the track - Rennlist Discussion Forums