I seriously doubt that Dempsey's gloves were loaded.
My grandpap's all time favorite fighter was Jack Dempsey & because of that, I've always liked him. I've read about as much on him as I have on almost any other fighter. And the question that begs to be asked is WHY would Jack have to load up his gloves for to beat Willard? Loaded or not, Dempsey was going to win that fight that day.
I'm aware of Kearns betting big on Dempsey to KO1 Willard (for anyone who thinks that may have been the motivation.) However, I think Kearns thought that Dempsey could KO1 Willard anyway, & didn't need to load the gloves. Had he gotten caught doing something that wasn't even needed to win, Dempsey's career would have been ruined. And Kearns wanted to milk all he could from Dempsey. Why would he risk all those future paydays by taking a chance like loading up Jack's gloves???
All that being said, a famous man who I can't remember his name, once said "If you want to win really, really bad, cheating will help you!"