Blackbird vulnerability

For Blackbird fanatics here is a clue about its vulnerability:

“Oct.30,1967 one A-12, piloted by Sullivan, was slightly damaged by SAM-2 missile detonation. Post flight inspection detected that small piece of metal had penetrated right wing.” – SR-71, Aerofax series.

So, it is absolutely clear that it could have been shot down on one of the next missions.