@Aaronaught: At RBC, at least, you have the option of paying off the mortgage early (
with all the
associated penalties), transferring the mortgage to your new house at the old interest rate and terms, or transferring the mortgage to
whomever buys your house (again at the existing rate).
Whomever is determined to be the guilty party is then (along
with his or her car insurance company) responsible for all the costs
associated with medical treatment and property damage for both parties.