COTD: Linear momentum of poop edition

In calculating whether or not bird poop can crack a windshield, one must consider correctly the rigidity of the fecal materials in question. Science is funny that way.

Jip1080 disagrees with the underlying methodology behind calculating the plausibility of bird poop cracking a car windshield. And he's got a theory to back it up. That is, that bird poop isn't rigid, in a scientific sense. Off we go, professor:

The assumption that the poop is ridged [sic — rigid] (poop is also not a non-Newtonian fluid*...) and the full mass can be used to calculate the initial impact force or the impact force at any point through the duration of the collision as if it were a ridged [sic] object would be incorrect. The impact force at any given time would likely be a decent amount less than calculated. With this added tidbit...

...you should start looking for the f*cker who hit your windshield with a rock and then shit on your car.

*unless the bird / person ate a metric sh*tton of cornstarch possibly.

Wait, bird/person? Cornstarch? I've seen this movie before, and I think it's illegal in 10 states.