what is the criticalnote on huckleberryfinn and jim relationship

Critical note would just mean the major incident. I don't think Twain meant there to be a major incident when Huck simply started respecting Jim. This happens gradually. Certainly Huck is pre-desposed to having an open mind. He is not shackled so much by Southern white racism. Jim and Huck simply becom friends and confidants, Certainly when Huck Jim compliments Jim on his escape job (better than the great Tom Sawyer) they became kindered spirits.

"Then I jumped in the canoe and dug out for our place, a mile and half below, as hard as I could go. I landed, and slopped through the timber and up the ridge and into the cavern. There Jim laid, sound asleep on the ground. I roused him out and says: “Git up and hump yourself, Jim! There ain’t a minute to lose. They’re after us!” (Chapter 11)

I believe the critical note between the two characters occurs in response to this incident. Huck has just left town and returned to where he and Jim had made camp. If you look closely at the wording, you'll see that Huck is well aware the trackers (slave hunters) are only concerned with Jim's whereabouts......... this is the moment Huck truly casts his lot in helping Jim escape rather than turn him in. There's no longer a question here, and although moral convictions will continue to plague Huck at certain times throughout the course of the novel.......... Huck means what he says when he excitedly says, "They're after us!"

OOps I meant when Jim complements Huck on his escape job from Pap.