The acounts that I have read paint a verry different picture. Carpinter was beating Smith handily untill the bout was ended by a foul. Smith might just have fouled out. Either way, Smith lost by a foul while far behind. This would be like a light heavyweight champion today winning the WBO heavyweight title.
Smith won the 1st round, and was ahead with a knockdown in the 6th. Carpentier won the 2nd and 4th rounds, a KD in the 4th. In the 3rd and 5th neither had an advantage, and on points it would have been even after the 6th round. There was no "beating handily" except if you go by the BS that Eugene Corri wrote in his memoirs, he had Carpentier winning rounds 2-5, with 1st round even. Plus both him and Carpentier in his autobiography claim Georges slipped and it wasn't a KD, as no punch landed. I've read other versions, plus several days later another piece from London was published that a private view of the film was held, and it could be seen that Smith landed two punches to the jaw, and the other punch that was foul barely grazed Carpentier's shoulder (despite what Georges himself writes in his bio about a hard punch behind the ear).
Carpentier, of course, claimed he was perfectly well and wanted to continue, if not for his manager insisting that he stayed down, such convenient and manly conduct. They also agreed immediately that they wanted a rematch, they didn't want to win on a foul, but just several days later they claimed they wanted to meet Wells again (what for, one may wonder), and put aside the talks of a rematch with Smith.
Strikes me that Loughran remembered it very clearly in fact ,even recollecting,what punch hurt him what round ,and what round he dropped Carpentier.Loughran lived a long life and retained all his faculties,he was on the lecture circuit as an old man ,still lucid an insightful,I would take his word over other accounts,especially as it was a taped interview.