This can't be more obvious, so Head doctor is Tooru stand, we know its main ability is the calamity pursue, and when you are affected by it you can see the doctor like if he is pursuing you, then we can see is a super powerful stand, can affect multiple people at the same time so this could be...
So the dad was a rock? Or the clip was a rock? Her father died and it was a stand or his pet rock? Or yasuho’s mom knew her husband died and that's why she doesn't want Yasuho to visit him? or both didn't knew he died and he used the clip for notice Yasuho about that? damn I'm so confused and...
No, this isn't character develop, what did Joshu learn? Did he mentally grown? No and no, this is just a unnecessary arc, it's like Araki wanted to give Joshu some protagonism and develop, but that don't worked at all.