Drawing The Wrong Conclusion

HERE is my game against the top seed in round two of Northwick Park.
Spanton (1951/168) - Thomas Bonn (2199/201)
Sicilian Closed
1.e4 c5 2.Nc3 a6
This may have been first played by Frank Marshall in two wins at Scheveningen 1905. Black continues to score very well with it.
3.g3 b5 4.Bg2 Bb7 5.d3
The non-committal main move.
5...e6 6.a3!?
Not a popular choice, to say the least, but it has been played by Leonid Kritz (2571). The main move is 6.f4, and if 6...b4, Stockfish10 and Komodo10 like 7.Na4!?, when they consider 7...Bc6 8.b3 Bxa4 9.bxa4 as good for White.
6...d5 7.exd5 Nf6!? 8.Nge2 Nxd5 9.0-0 Nxc3 10.Nxc3 Bxg2 11.Kxg2 Nc6 12.Be3 Nd4 13.Bxd4!?
This has been played by a 2305, but is not liked by the engines.
13...cxd4 14.Ne4
An easy improvement on 14.Qf3?? dxc3 15.Qc6+ Ke7, Klaus Neumeier (2305) - Ralf Lau (2495), Austrian Championship 2001 (0-1, 47 moves).
14...Be7 15.a4!?
Trying to induce Black to put another pawn on a dark square (his only minor piece is a dark-squared bishop).
15...0-0 16.f4 f5!?
Very double-edged. Black seizes the initiative, but creates weaknesses on the e file.
17.Nd2 g5 18.Qe2 Qd5+ 19.Qf3 Rac8 20.Qxd5 exd5 21.Rfc1?!
Passive. The engines give 21.axb5 Rxc2 22.Rf2 axb5 23.Nf3 Rxf2+ 24.Kxf2 with what they reckon is a dead-equal position.
21...gxf4 22.gxf4 Bd6
The engines give Black a slight edge after 22...b4.
23.Kf3 Rfe8 24.Nf1
I rejected 24.axb5 because of 24...Re3+, but the engines reckon 25.Kf2 axb5 26.Nb3 Bxf4 27.Nxd4 is equal.
24...b4 25.c3?
The engines give 25.Re1 Rxe1 26.Rxe1 Rxc2 27.Re6 Bc5 28.Rxa6 Rxb2 as only slightly better for Black.
25...bxc3?!
Even stronger is 25...dxc3 26.bxc3 b3.
26.bxc3 dxc3 27.Ne3 Kf7?
Better is 27...d4 28.Nxf5 Bc5.
28.Nxd5 Red8

Black offered a draw here - should White accept? 

*****
*****
*****
*****
*****
I always have conflicting emotions when a much higher-rated opponent offers a draw. On the one hand I assume he must dislike his position; on the other hand a draw against, in this case, a player rated 248 elo higher is not to be sniffed at. On this occasion there was the added factor that Black was getting short of time, and I now suspect this was the main (only?) reason for his draw offer.
29.Rxc3?!
Not a practical decision. White's win of a pawn is only temporary, and meanwhile Black has the better minor piece.
29...Rxc3 30.Nxc3 Bb4 31.Na2??
Black is only a little better after 31.Ne2 Rxd3+ 32.Kg2.
31...Rxd3+ 32.Ke2 Ra3 0-1