Married 20+ years with kids

My youngest is now 17 and has not always been entirely honest about things that happen, so it’s hard to know when they are truthful or lying. That being said, I never want them to feel unloved or unsupported.
Last night as I was resting before my night shift, my 17yo. Got sassy with dad over filling the dishwasher. Dad said, “you’re grounded, give me your phone.”
Both parties said my teen refused and it escalated with dad taking the phone away.
My teen claims dad left two scratches on the thigh when taking the phone. There are indeed two scratches on upper, outer thigh about 3 inches long, but they are awfully thin to be from fingernails. (not saying impossible, just suspicious)
Dad said he grabbed the phone but no way did he scratch our teen. Dad did however apologize for hurting our teen at my urging. Would you agree to apologize if you didn’t do it? (Suspicious)
There was an incident years ago where CPS was called by a counselor (our then child), was seeing. It was found unsubstantiated because our child kept changing their story.
My husband does have anger issues as does our teen.
I do not want either of them to feel I’m against them or that I’m not supporting them. It was only the two in the room. No witnesses.
I reminded my husband that it is never okay to leave marks on a child as it could be seen as child abuse. All he said was, “I know.”
I work in healthcare and am a mandated reporter. What the heck do I do?
If it was caused by my husband, it should be addressed. If not, he could lose his livelihood since he also works in healthcare if he is found guilty.
I love them both but am torn between what to do. Our teen will be a senior in high school this year, so part of me just prays we can make it through the next year. The other part of me is upset that anyone would hurt my baby and I feel the need to protect them at any cost.
Thank you for any advice.