I'm not sure if this would have anything to do with it, especially being as it appears to have happened at least a couple of hours before the bbs went down, but I just located the following (new, at least to me) error that
ended up in the log:

Sat Dec 13 2014 00:20:39 tinfoil.synchro.net
0037 !ERROR 22 setting socket option (RCVBUF, 4098) to 8192

I don't know if that helps at all, but I thought I'd post it here just in case. As always, any feedback appreciated.

---
þ Synchronet þ Tinfoil Tetrahedron BBS telnet://tinfoil.synchro.net