I'm away from home for a few days.  When I received the large deposit, I waited for an hour or so to see if it was going to be immediately withdrawn.  It wasn't, so I sent it to the cold wallet.

Now its depositor is attempting to withdraw it from the hot wallet.  There aren't enough funds there, so the hot wallet is going dry, over and over.

I've no way of contacting him other than hoping he reads this post.  I'll be back at the cold wallet in a few days, and can cash you out in full then.  In the mean time please don't worry - your funds are safely stored offline.