Would this make wave a red flag for you?

My son is 18 months and his dad sees him 2 times a week for shorter visits then every other weekend. We tried a schedule that wasn’t working for our son and since his dad never bothered it’s within my right to pull back the progression or adjust it to what’s best for our son. He never puts his needs first, he was feeling unwell completely congested and just clearly not well and his dad took him boating instead of prioritizing his nap so he came home entirely limp and dehydrated. He regularly comes home completely filthy with a nasty diaper rash (he has NEVER had one with me) and either dried poop on his butt or a REALLY full diaper, which granted he does sometimes pee a ton at once. Upon pick up he gets really upset because his dad hasn’t bothered to be there, his fiance does it. He comes home and is off for a day or so, fussy, clingy, easily aggravated, etc. he’s general such a happy dude and so stinkin sweet but he does have normal toddler emotions of getting frustrated when he can’t do something, pushing limits, etc. his dad claims he is never crying never upset only happy with him, which is alarming to me that he feels unsafe to have normal emotions that toddlers and he has/have. I feel like it’s yet another sign of neglect/abuse. His dad is mentally unstable and an alcoholic but I’ve been unable to prove in court since he somehow has avoided conviction despite regularly engaging in reckless behavior. I know that for example he yelled at him to “go to sleep” when he stood in his crib and boasts about it. I’m worried he’s ok a sense putting on a show so he can get his needs met and it breaks my heart..it’s a red flag to me.