I know, I know, Grinder. Or, the accumulated clutter of many years, etc, etc. But you know how it is with dialogue. You hear in your head the rhythm of the character's speech and how he would express it, and it feels right - and then you want to put it that way, and not change it just because you get in a muddle with the apostrpphe(s).
Let the copy editor decide, I reckon. But I know how fellow pedants on here love a good grammar/punctuation teaser to argue about!