That is not the ground electrode, it is bonding the gas pipe (250.104(B))
He also could have said you bond to the circuit EGC "likely to energize" the pipe. That will usually be the largest piece of electrical equipment connected to the gas pipe. (range electric igniter, furnace blower etc)
He might even say that was the A/C compressor via the freon line set to the A coil in the furnace. The safest alternative is the GEC, then all bases are covered.


Greg Fretwell