I guess that means anyone who had BTC in their lending account took the loss, regardless of whether they had any active loans (or anything to do with CLAM).
I think you're misinterpreting what they wrote:
the principal of all active BTC loans as of 14:00 UTC today has been reduced by 16.202%
That's pretty clear: BTC loans which were active quite some time after the dump are the ones which took the haircut.