This seems problematic as is.  Correct me if I'm wrong, but as I'm reading it, this is going to make whatever key is bound to this action put the left mouse button down for as long as it's being held down.  This means that if the player moves their mouse to a location while walking out in the field, then puts this key down and just holds it down, that will cause it to detect a press-and-hold and will cause Twilight to start walking in that direction.

Due to this possibility for conflict, I really don't think we should be causing the keyboard to affect the stored state of the mouse like this.  I think much better would be to just have something in KeyboardHelper that returns a value indicating whether the key for this action has been pressed and released, and then use that alongside things detecting clicks from MouseHelper.  (Might be worthwhile to rename this action key from "click" to something like "continue", too.)