the grain of salt seems to be the canoeist, and you certainly have to take him into account. "swam after a canoe for over a mile" in snow melt water with no life jacket and probably no helmet.
the situation was scary yes, but that has little or nothing to do with you other than happenstance.
as in other posts though, the more time you spend on the river the more carnage you see and hence become accustomed to.
Enjoy that river class, should be fun for you guys!
I've never boated before, but I have posted a lot on Mountain Buzz!