I'm using a touchscreen smartphone to browse SO and I go to favourite a question. Through a combination of Homer-Simpson-style typing ability and the general lack of accuracy afforded by an oldish screen I hit downvote instead of the favourite star.
Now I find myself in a situation where I either leave the poor guy wish an erroneous -1 (and slight damage to my own rep) or give the guy +1 when I didn't think his question was either good nor bad. I simply wanted to see what answers were given.
What is the correct course of action?