Multiple hashes in lockfile

[winterqt]

In this lockfile, the entry for @matrix-org/olm contains two hashes. The higher quality algorithm (SHA-512 in this case) is the one actually used, but why is the other one (SHA-1) even included in the first place, and why just for this dependency?

I ask this since the current documentation for lockfiles states the following with regards to hashes:

integrity: A sha512 or sha1 Standard Subresource Integrity string for the artifact that was unpacked in this location.

which implies that only one hash will ever be in this field, which is correctly reflected in the other dependencies.