I have hesitated for a long time before posting as there is so much junk here however facts.
R2-5 is one of 11 relays connected in parallel. They are controlled by the left nose oleo switch. they are energised in the ground condition. R2-5 has four contacts used, they give air/ground state to : AC crosstie, AIR data sensor heating (specifically the RAT probe), TOCW and Radio Rack cooling (something to do with standby cooling).
Flight Recorder inputs from the same system are from several other of the 11 relays, R2-283, R2-58 and R2-212.
It is quite conceivable to me that R2-5 was failed in the de-energised position, i.e. the flight condition, while the remainder of the relays were operational.
The RAT probe heater has it's own cb.
I have thought about this for a long time and as a line engineer, under pressure with a full a/c RTS then I think I would have just pulled the heater cb and dispatched iaw the MEL. The other circuits controlled by that relay are not ones with obvious symptoms.
The Facts are just that, the remainder my opinion only.
The report is needed, it will be interesting to see if 2-5 can be found and it's serviceability established.