"Jed" wrote in :

First, about an hour into the flight I smelled what seemed like jet
engine exhaust. That lasted for about 10 minutes.

Flatulence?

The other was really strange (at least to me). About 30 minutes later,
the First Officer exited the cockpit and walked the length of the cabin
with his arms outstretched, hands running along the overhead
compartments. Then he walked back and re-entered the cockpit; when the
door opened I saw that a flight attendant was waiting inside. He went
in; she came out.

Was the bathroom in the rear of the airplane?