The pillow scene

I guess they are just following others in TV/movie land but yeah you don't really kill a person by holding a pillow over someones face for few seconds. It would take minutes of them fighting you to pass out and then minutes more after they pass out for them to actually die.

To be fair they in general often make something seem quicker than it actually is to save up valuable airtime. It would be less annoying though if they would make the character hold the pillow a little longer rather than to let go immediately once the victim passes out.