Cassidy combat roll gives CC reduction

I landed a mei ult on a baptiste + cassidy. There was no kiriko on their team to cleanse. There was no lifeweaver on their team to pull him out of it. The cassidy used combat roll right before being frozen and broke out a little over 1 second later. The baptiste was frozen the full duration of about 4-5 seconds. I’m pretty sure his combat roll is giving 75% CC reduction and I couldn’t find it anywhere that this is intentional.