Its perfectly legal for the photographer to fly the machine never mind operate the fuel tank selector.
I respectfully disagree.
A person shall not act as a flight crew member of a
civil aeroplane/helicopter registered in a JAA Member
State unless that person holds a valid licence and
rating complying with the requirements of JAR-FCL
and appropriate to the duties being performed, or an
authorisation as set out in JAR-FCL 1.085/2.085 and/or
1.230/2.230.
Shirely manipulating the controls of the aircraft is 'acting as a flight crew member'? I'd imagine that's what an insurer would say anyway...