It's ok if for the sake of semantics you want to compare Sam Colt's revolutionary design to the pepper box or the revolving flintlock.
Not semantics in any shape, form or fashion. Historical fact. The flintlock above, an improvement over the pepperbox, is a revolver by any definition of the word. No, it does not fit your narrow view of what a revolver should be but that does not change what it is nor does that change the fact that they predated Sam Colt's design for the Paterson. I am sorry to gore your sacred goat but it is unabashed historical fact, not my humble opinion. John Taffin, well known writer and sixgun fancier, would agree with me and does, in print.
What do you suggest we call them in lieu of 'inventor'?
You can call him whatever you like. You can say that he designed the first mass produced revolver, he successfully adapted percussion caps to the design, he successfully sold the concept to the military and that his designs have been extremely influential in the industry to this day. There are a great many things to be said of the man, you just cannot say that he originated the concept or the execution of the first revolver. That singular fact does not diminish what he did accomplish. As I said before, three times, he may not have invented the revolver but he did make it practical. His designs led directly to the legendary Single Action Army of 1873. It is a fitting tribute that so many of his designs are available today as reproductions. Even Bill Ruger's first single actions were changed very little from the Colt design, before they were fully modernized (for the lawyers!) in 1973.
I am not comparing the different designs as if it were a competition. I do not care to argue the merits of each. History is what it is. They are very different firearms from two very different eras but the simple fact remains that the revolver was around long before Samuel Colt.
I am also not seeking to dethrone the legend. I own more traditional single action revolvers than any other type of firearm. Over two dozen if I remember right. All guns that owe their lineage to Sam Colt in one way or another.