My relative was suspended two days from school for not telling a teacher about a crime he witnessed. Is it fair?

The middle school student was standing in a hallway with two other boys -- one of which he knew, but was not friends with. That boy noticed the locker right next to my relative's locker had something valuable in it. That boy then pried the locker open and snagged the item out of it. My relative said he didn't tell a teacher about it because he was afraid of retribution.

The school suspended my relative and the third boy for two days for not reporting the incident. There should have been a consequence, but suspended two days for an act he didn't commit, but only witnessed?

What do you think?