That´s true that shoot placement is one of the keys for a sucessfull hunting.But,in this case,bowhunting wild boar,also the type of broadhead and its weight is very important.
Here,the wild boar (mainly the male)has a very thick hide in the vitals area that helps to protect from the tusks from anothers male,specially during the rut season.The thickness and hardness of this part of the skin is incredible.We call this part "escudo"(shield).
I have seen mechanical broadheads failing,00 shoots that didn´t penetrate and also people with problems to reach the vitals with a knife due to the hardness.
I try to do it the best possible and use a good broadhead with a heavy arrow.
That wild boar in picture(about 3 years old) ,with a weight around 200 pounds,has a hard skin with a weight around 50 pounds.Normally,the older the male the bigger the shield.
I don´t know if it is the same in your State.
Thanks for your comments.Good hunting ¡¡¡