On the subject of walk-offs for Scutaro, his walkoff HR against Rivera was one of only 5 he's allowed, the others were to Bill Selby, Bill Mueller (I vaguely recall that), Vernon Wells, and Ichiro.
EDIT: And, I never would have guessed, the team he's given up the most homers to in his career is Baltimore, not Boston.
Also, he's only given up back-to-back home runs once.