Pawn and Two: At move 33, Keres had an opportunity to obtain satisfactory play and an approximately equal position with 33...Ng7!.
Botvinnik states the following: <In the special issue of '64' (No. 7) Alatortsev correctly notes that after 33...Ng7 with the threat f5 (34.Rf3, Nh5) Black would have obtained satisfactory play.>
Fritz 9 agrees that 33...Ng7 is Black's best move. Fritz gives an evaluation of (.28) (18 ply) and suggests 34.Rc1 Rdc8 as the best continuation.
After 33...Ng7 34.Rc1 Rdc8, here are a few of Fritz's evaluations and suggested continuations:
(.00) (19 ply) 35.Rxc8+ Rxc8 36.Re3 f5 37.Bb1 Rc4. Or 37.Kh2 fxe4 38.Bxe4 Nf5.
(.00) (.19 ply) 35.Qh6 f5 36.Rf3 fxe4 37.Bxe4 Rc4.
(-.01) (19 ply) 35.Re3 Rxc1+ 36.Nxc1 Qd8 37.Rf3 f5.
(-.02) (19 ply) 35.Rc2 Rxc2 36.Bxc2 Rc8 37.Bd3 Qd8.
There are many other variations and I am sure improvements can be found for both Black and White. However, I believe Botvinnik's and Alatortsev's opinion that Black can obtain satisfactory play after 33...Ng7 is correct.