Lawyering the language on airline application questions is fraught with peril.
My recommendation is that if there's any grey area at all, take the most conservative approach.
I personally would consider that an incident if I were filling out an app. Also if I was doing the interview. An employer's idea of an incident may not follow the letter of the NTSB rules. If the question was whether you had to report it to the NTSB, then you could split hairs. I wouldn't do it with an employer though.
Not sure about PRIA, but a FOIA request would almost certainly return the 709 ride and any employer is going to want to know the story there. Some airlines do FOIA requests as a matter of course, and anyone could do one.
Also, when addressing this at an interview... if it wasn't a gear up, does that mean you did a go-around after a prop-strike? That's going to raise some questions right there, high risk of engine failure at go-around power after a prop strike. You'll want to consider how to address that, ie didn't actually realized you'd hit the props, or what your logic was and what you learned.