Sure. But the risk of death in a cyclist-ped collision at 5 mph (<1%) is several times less than the risk of death (>50%) in a car-bicyclist collision at 35 mph. I don't think anyone here is debating what he should have been doing.
Er, OP suggested he should have been on the sidewalk. Which is fine, if you're actually riding at 5mph. I've never seen anyone ride that slow.