When uninverted Kat got shot by inverted Sator in Tenet, in forward perspective the hole on the wall was fixed but Kat wasn't. What is the difference between Kat and the wall? Shouldn't they both get fixed after being shot? And if assuming this is how this universe works, in the airport sence the inverted protagonist got stabbed by an uninverted protagonist. Why did the inverted protagonist heal after being stabbed but Kat didn't?