[z28jd]

RBI's weren't officially kept until 1920, so while I don't know the answer to your question, I can't imagine anyone thought Ty Cobb won the Triple Crown in 1909 by leading in an unofficial stat. If the term was used for Cobb, or anyone before 1920, it wasn't anything MLB recognized.

When Paul Hines "won" the first Triple Crown in 1878, there was no RBI stat and for many years, Abner Dalrymple was credited with the batting crown that season, so Hines definitely didn't know he won the Triple Crown. He was credited with it after he passed away.

The next three winners,Tip O'Neill, Hugh Duffy and Nap Lajoie wouldn't have known either because RBI's weren't even tabulated (something that was done from 1907-19, but not an official stat).

It's possible Medwick was the first, and it also could have been something that someone came up with for future reference and he just happened to be the first who led in all three.