I pulled apart thisDevice Handler, and I didnt see anywhere that a double event would be sent.
What I find odd is that Ive re-installed it several times, and I could have sworn at one point all buttons were triggering multiple, and now only button 1 and 4 are. Which is also off, as the @uberrob is seeing buttons 2 and 3 throw multiple. Again, I could have sworn on one install they all were throwing multiple.