"I can't see someone in this person's position as being a risk to a healthy party of 2 or 4 people."

depends on how you define risk I guess - I could see some nutcase sneaking into a camp at night and stealing your canoe and food bag - that alone would be really unpleasant if it was your only canoe and you were in the middle of Q.  hell if it was me (It's not, me, is it?) I'd steal all your canoes so you couldn't go for help, and I'd be more mobile.