Let's see, mgkdk made the hammer after my vote. I unvoted, then Shawn came in. I'm thinking that one of these two are scum, perhaps part of the scum team.
It is true that a scum tactic might be to mislead, but since unknownspeedster wasn't any real threat, eliminating him as you did makes it look less suspicious to the passer by. However, I feel this still gives you a slight scummy out look, not saying you are scum quite yet, but your hammer + unknownspeedster's demise is shining a bad light upon yourself.
I'll be fair for now and only FoS: Shawn, mgkdk