Am I getting experience when Ryuji insta-kills the enemy?

After reaching a certain rank with Ryuji (8, I think?), he gains the ability to have a chance to insta-kill an enemy when you Ambush them.

While traversing Mementos, this happens quite frequently. I know that it normally gives me the mask of an enemy I would've had to fight (it tells me I can't carry another mask most of the time), but is this giving me any experience? I'd hate for all these insta-kills to be causing me to miss out on experience.

Ryuji's instant kill ability does not give you EXP when it triggers, however it is important to note that constant activation of this ability may be a telling sign that you are overleveled for the area because this ability occurs more frequently when you are ambushing enemies that are significantly weaker than you are meaning you wouldn't be getting much EXP to begin with if you did attack them.

If you do want to get the EXP from these enemies your best bet is to let them spot you before you attack so you prevent yourself from ambushing them.