DB,
As Sid has already pointed out, in his aircraft and the majority of aircraft in his operation's fleet, the RADALT is connected to the battery bus - this mod was done post and as a direct result of the Glasgow incident.
G-SPAO was airframe serial No 0546 and not modified in the manner described.
With reference to "implying an attempted relight", as you are already type rated on the 135 you will know that for In Flight Engine Restart, "Prime Pump ON" is step 7, "Engine Switch OFF" is Step 4 - Both Engine Switches were found at FLIGHT and Gated.
There was no attempted relight.