Yeah, that is effectively what happened, but officially Gorton was elected as leader of the Libs (beating Paul Hasluck iirc). Since he was in the Senate he could not become PM until after he transferred to the lower house. So Black Jack McEwan held the PM status until Gorton could be parachuted in.
for the record, I think Gorton was the most honest of the Lib PMs - not that he has had much to beat. He was a fighter pilot in WW2 so was not a typical Lib blue-blood.