You think that after they lost 1800 BTC...
I heard that they passed that loss on to their customers - that all the people who were lending out BTC at some point about a week after the dump took the loss, whether they had loans active at the time of the big CLAM dump or not.
"Today
[June 7th], we recognized the generalized loss across lenders in the BTC margin lending pool. As a result, the principal of all active BTC loans as of 14:00 UTC today has been reduced by 16.202%. This action impacted 0.4% of Poloniex users."
My understanding is that any funds you loan are stored in a separate account at Poloniex, so 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).