Just a thought, FLY
But are you assuming the T7 has a separate supply, isolated from the pumps/line that "takes over" when Pumps inop? The mass of Fuel in the pipeline has great inertia at low/no velocity and with HP functional at 14psi (or slightly greater) could vaporise regardless of Temp. One atmosphere is ~ 14psi, right? In a "tail low" approach, the suction problem could be exacerbated by the inertia of the Fuel and its lethargic velocity in the Line due to Green descent. Haven't we been there? (Besides, the pumps were working, AAIB)
Airfoil