Protocol forced to V2 in low-memory conditions?

One of our customers seems to be running into exactly the issue hypothesized about by Tom here:

http://www.postgresql.org/message-id/8040.1314403175@sss.pgh.pa.us

That is, the server is in low-memory conditions, and the client occasionally issues an error saying it can't complete a certain action due to the protocol version:

PG::UnableToSend: function requires at least protocol version 3.0: SELECT ...

The server is 9.2.4, and the client is the Ruby pg gem using a 9.2.4 libpq.

Was the possibility of an inadvertent protocol downgrade addressed as part of that patch? I read through the thread, but it wasn't entirely clear.