Day hikers can protect their food. The nature of day hike is to be out of the wilderness before it is time to bed down...or should be. This is not applicable to this trip.
He had an overnight permit for the MMWT...the trip requires a canister and WAG bag...forest interpretation. This mean if he did not have something designed to keep bears from food he was in violation. Again, no one can be certain there are going to meet their schedule...illness or injury.
If you pass through an area with these regs, you have to have a canister. Yosemite and Rae Lakes have canister regs.
There are surely local regs that are involved here, too.
