Verbal Declaration on the end

[Rico Suave]

A seemingly experienced live player raises preflop, folded to a young kid in the BB who calls. Flop is AAK, turn is blank, river is blank and the BB check calls the pfr on each street.

When the BB calls the river bet the pfr says, (and this is an accurate quote) "You got it...(slight pause).......you must have something." The BB then hold his cards up--AJ--so the the pfr and most of the table can see it (not the dealer, however)...the pfr nods, kind of smiles, and the BB throws his cards face down next to the muck.

The preflop raiser, who has yet to muck his cards claims that the pot is now his, and starts to raise a stink, and calls the floor. (this is not a high limit game btw)

My question, does verbal declaration of concession carry any weight at all?

Thanks.

--Rico