The problem isn't that the sight tool won't fit in between the protective ears; it will.  The problem is that the sight tool's cavity is only deep enough to fit the front sight post in the center, which is fine for adjusting a standard front sight.  The Trijicon front sight post isn't square; it's rectangular, and the top edges hit the interior of the tool before the teeth reach the adjustment plate.

It's easy to fix though.  Simply find a drill bit that barely fits into the hole, and drill all the way through the sight tool.  I modified two of them that way, and they work great on every rifle I've ever tried.

-Troy