Phony Benoni: In team tournaments, match considerations often take precedence over what is happening on the board. If it is better for the team to take a draw in a particular game, it's practically your duty to do so. Sometimes "package deals" are arranged, determining the results on several boards. That being said, I don't know what the reasoning was here. Boleslavsky's team was winning the match (USSR vs. Czechoslovakia) fairly comfortably despite losses by Smyslov and Tal, so it wasn't necessary to press for the win. He may have been looking for a bit of a rest.
Here are the other games of the match, if that means anything:
1 Filip vs Smyslov, 1957 1-0, 43
2 Keres vs Pachman, 1957 1-0, 33
3 F Zita vs Bronstein, 1957 0-1, 37
4 Tal vs J Kozma, 1957 0-1, 32
5 J Sefc vs Petrosian, 1957 0-1, 96
6 Taimanov vs J Fichtl, 1957 1/2, 76
7 F Pithart vs Korchnoi, 1957 0-1, 44
8 Tolush vs J Rejfir, 1957 1/2, 30
9 J Jezek vs Boleslavsky, 1957 1/2, 23
10 Averbakh vs Ujtelky, 1957 1-0, 46
The position seems balanced, though I rather like Black's position a bit better. His pieces seem a little better co-ordinated.