Yes you are. The snapshot is just to get a transactionally-consistent view of the data. The only pages in the snapshot are ones that are changing at the time that CheckDB is running, if the source for those were damaged, you'd be getting massive errors during the copy-on-write process and the concurrent access anyway.

Saying that a snapshot means that the original data doesn't get checked means that the hidden snapshot is also not acceptable (it's on the same logical drive, not necessarily the same physical disk, definitely not the same spot on the disk), so you're advocating CheckDB with table locks as the only acceptable option.