Badly annotated games are so funny, 27...Bb6 (forced, to avoid Rxc5 followed by Rc1, with White's advantage.) LOL 27...c4 thank you for the extra pawn, 27.Rac1 even gets an exclam
Rxb4 is a blunder, and even in the position you posted whitout the pawn on d5 it's a bad move since there white has Rc4 that simply wins a bishop whereas Rxb4 gives up a rook.
Try to find one of the best moves I have ever seen here. White seems very bad, as the c5 pawn seems dead and Black's rooks will be more active.
That is not the real position, because I won in fact the game because of an additional e5 pawn from the Caro-Kahn, but for overlooking the answer I diserved to lose.
The answer is Rxb4 !! See there :
A hard game !