Bulletproof windshields were very common during this period, although 43-11719 doesn't appear to have been fitted with one, likely because the F variant never advanced beyond the prototype stage.
I may have missed it, but I don't see anywhere in that linked article that mentions bullet proof windscreens... and Wikipedia for the aircraft also makes no mention. Plus, we're not just talking about this particular aircraft in this incident, but generally all aircraft.
But, I would not be surprised it was tried, particularly with WWII era machines. There's very little actual benefit to having one on any aircraft, even CAS aircraft. A modernly restored version meant for airshows and racing probably would have replaced it for something more modern and lighter weight.
Look at the 12th photo in the gallery, which shows the cockpit from the right-hand door. No armored windscreen.
There's no particular reason for wikipedia to mention it because it was a very common feature in this era. It would be like mentioning that it had self-sealing fuel tanks. It was also a feature that could be present or not between different models, and could even be retrofitted to a plane once it was in service.
Regarding the wreck-finder below: he likely does know exactly what it was because he likely started by looking up the crash report (and based on his claimed date, it's probably s/n, 44-2031)
https://warbirdsnews.com/warbird-restorations/caf-bell-p-63f...