I go with ... flipped up windshield wiper blade, the bottom stabbed the cowling. Possibly when changing the wiper blades ???
Glad you ordered the part. Those small details drive me crazy. And it is not a long trip.
I try and leave a towel under my wiper blade when changing them, for just this reason.

 

looks like melted plactic to me

 

Even worse - I've read posts where folks forget to lower the wiper blades before opening the hood.

 

I was changing my blades on my suburban. Push push push to get the blade to disengage. Flicked the bare metal wiper arm into the windshield. Big spider crack from the arm tip impact. Then very foul language, and many verbs in once sentence.
Thus the drop cloth under the wiper arm trick.
Gentleman in the office left his gas cap off... then drove through the car wash.