Dude I seriously doubt your credentials.
Kissing (Deep Kissing) is definitely a risk factor for transmission of HIV.
Do you check each others mouth for presence of cuts or ulcers or bleeding. Seriously???
Definitely his question was about DFK. But how can you expect him to ask you about cuts or ulcers or bleeding gums? You have claimed to be a doctor so it's your duty to cover all the aspects related.
Low risk does not mean No Risk.
I would again mention here capital letters. KISSING IS A LISTED RISK FOR HIV TRANSMISSION.
Please make sure hence forth you give detailed information. It's a question of someone's life.
Please go through the link guys. This will give you a basic info.
https://www.cdc.gov/hiv/basics/transmission.html