Maybe Jasper was having a bit of an off day thats why he acted out of character. I'm sure if I had a bit of a headache and someone started shaving my head I'd snap a bit
My mum and step-dad used to have a staffie male. He had lived with my step-dad from a pup and moved in with my mum when he was about 13 years old, he didn't know her before then, she didn't feed him, didn't walk him, didn't particulary do anything with him. She just saw him as my step-dads dog that now lived with them......
Anyhow Sam (dogs name) absolutely loved my mum and followed her everywhere. Noone ever did figure out why mum ended up the favourite even though my step-dad did everything for him and at the time my sister and I still lived at home and played with Sam and walked him etc, but when my mum was there noone got a look in. Don't know whether its because my mum was the boss at home and he saw her somehow as top dog? They are funny creatures lol