BBM- Well, of course, this is just my opinion, but I would say yes. When a married couple is in the process of divorcing, two things are often at the center of the battles: Money and the children.
From my own experience, when I was a child, my parents fought constantly. There was plenty of loud arguing and cursing at each other all the time. There was not physical abuse, but lots of angry verbal emotional battling going on. Many of their fights would lead to the inevitable "divorce talk". I remember many angry statements such as, "Well, I'll just take the kids and leave. You'll never see them again!" Always followed by, "You'll never take my kids away from me". Money and other marital assets would always be worked in there, too. Sometimes threats of exposing each others' "flaws" to friends, family, coworkers, etc.
I recall someone suggesting that the reason Gail may have called the police
on the day of the incident with the car and what vehicle would be driven by whom to the lake house was because the children were terrified when it resulted in MP exiting the vehicle and walking away. This caused a sort of flashback for me when my brother and I were about 6-7 yrs old and on a day trip with my parents in the car out in the middle of nowhere and they had one of their infamous arguments escalating to the divorce talk and my mother demanded my Dad stop the car on the side of the road and get out. I remember my little brother and I were hysterical. We were out on a country road in the middle of nowhere and in my mind at the time, if my father got out of the car, I would never see him again. I was too young to understand he would have been okay. Of course, my mother pulled away and then turned around and picked him up.
I can completely relate to kids who have to grow up witnessing this kind of behavior and the fear, sadness and guilt it instills. Sometimes you feel like it's your fault when you're a kid. I always tell people, don't do that in front of your kids. You have no idea what it does to them and how long it stays with them. Many of the arguments my parents had are still with me to this day.
My parents never did divorce, although they came close many times. I eventually learned it didn't have anything to do with me, it was just their problems. I broke the cycle, too. I never allowed my child to be exposed to any of that.
Sorry for the lengthy answer, but in my experience, I think it is highly likely that the custody issue was part of the arguments. JMHO