presumably responding as if the question asked if they favored offshore drilling in general.
Why do you presume that?
Certainly, it's not particularly probable that most people would rationally update in favor of drilling, but it's perfectly possible that significant numbers of people acting irrationally would respond to attacks on drilling by becoming more strongly in favor of drilling than before the attacks. Increasing fanaticism when under siege is not an unprecedented reaction in human psychology.
people acting irrationally would respond to attacks on drilling by becoming more strongly in favor of drilling than before
In studies I've seen showing this effect, people deny it in themselves. It is an embarrassing thing if true, I think that's obvious. I expect people to misunderstand or mis-think the question rather than answer honestly after accurate introspection.
the attacks
I think it was an accident.
A article in the Atlantic, linked to by someone on the unofficial LW IRC channel caught my eye. Nothing all that new for LessWrong readers, but still it is good to see any mention of such biases in mainstream media.
I break here to comment that I don't see why we would expect this to be so given the reality of academia.