"The honest cajun" joke

I heard this one on the radio, offered up by a Cajun cafe owner in Louisiana, so read it with a French Cajun accent...
Leetle Jean and heez father lived down on zee bayou. Jean wuz a very strong boy for all of heez ten years of age. One day Jean's papa asked Jean if he wuz zee one who had pooshed their outhouse into zee waters of zee bayou.
"Oh, no, Papa. I deed not do it!" say zee boy.
Now, Jean's papa knew that zee boy had a mean streak, and being zee strong youngun that he wuz, he wuz certain that Jean must have done zee deed.
He says: "Jean, now I really want you to tell me zee truth. Did you tip zee outhouse into zee bayou?"
"Oh, no, Papa. I wouldn't do that!" say leetle Jean.
Then Jean's Papa decides he must somehow win Jean's confidence to tell zee truth. He tells him zee following story.
"Jean, oncest upon a time, our first president, George Washington, wuz a leetle boy jus' like you. One day heez papa asked heem who had chopped down their cherry tree. Leetle George said 'Papa, I cannot tell a lie. I chopped down zee cherry tree.' And with that George's papa thanked leetle George for his honesty and all wuz forgiven."
"So, now, boy," says Jean's papa, "... let me ask you zee question again, and I'm only a goin' tuh ask it this one last time... Did you poosh our outhouse into zee bayou?"
Leetle Jean stares at heez papa for a few seconds in silence, and then he say: "Yes, Papa, I cannot tell a lie. I pooshed zee outhouse into the bayou."
With that answer, Jean's father slapped the boy to zee ground. He took off heez belt and began a whuppin' and thrashin' zee boy something awful. Leetle Jean through heez yelps and heez tears shouted at heez papa and he say: "Papa, why do you whup me? You tell me zee story about George Washington and how heez papa didn't whup heem when he wuz honest about cutting down zee cherry tree!"
Then Jean's papa, he say: "Yeah, but when George Washington chopped down zee cherry tree, heez papa wasn't a sittin' in it!"