Outside of five games for the Sharks, he's played his entire career for Toronto. That includes 32 games from this season: 32 games over which he posted a .918 save percentage, rebounding from the .907 save percentage he had the year before. Reimer had a great season on what was very clearly a rebuilding team, and for that, he's getting some recognition - even though he isn't on that team anymore.
Or, as Scott puts it:
James Reimer’s such a nice guy that he got nominated for the nice guy award with a team he doesn’t even play for.— Scott Wheeler (@scottcwheeler) March 28, 2016
That's epic levels of being a nice guy. This works nicely.