I didn't get that deep into the conversation with the person. But it came from someone who sits in the action end of the aircraft.
I would imagine that your conversations would get pretty boring if you went into the level of detail of "the second window on the left in the cockpit."
I'm guessing the hammer was found inside the cockpit.
Rumour being that it was someone that has lost out on a lot of work with Alliance coming into Auckland and doing the work that they are doing.
Mower damage would be unlikely with the way they park the aircraft at Air Center One, usually its with the tail hanging out over the grass so the nose is pointing inwards onto the ramp.
Would take an ACME style ricochet off a lamppost for it to hit the window.