I have encountered the wrong pin-out on transistors purporting to be BS170s that I ordered from China.
These have the source and drain swapped over (see attached photo), so I I had to fit them "backwards" compared to the slik-screen?on the transceiver I was building (a (tr)uSDX). The transceiver worked fine with these dodgy transistors fitted backwards, but? they were almost certainly not genuine Fairchild parts.