Forgetting a child IS irresponsible.
It is, but it happens. Piling on at this point doesn't help things though. We'll see what comes out of the investigation.
My dad worked with a guy who was out working in the yard all day on a weekend day and his kids are out in the front with him. He went to back up his cars, thinking all his kids were out of the way, and ran over his toddler. As soon as he hit him, he realized what had happened and stopped the car got out and picked up his son running around the yard holding his lifeless son screaming "my son! My son! I've killed my son!" Would you convict him? How do you convict him? Would you pile on to him at this point? He killed his child. It was an accident. He has to live with the guilt that he accidentally killed his child. Is there a more torturous punishment than anything the justice system can do to you? I don't think so.
So yes, forgetting a child is irresponsible. Again, it happens and there tons of circumstances that cause this. It happens in all walks of life across all socio-economic strata. I just don't think this guy can feel any worse now than he already does if it was purely an oversight on his part. I can't imagine having to live the rest of my life with that guilt.
Let me throw another one at you because this hit close to home for me. One of my dear friends who is one of the smartest people I know. He's an accounting professor and his dad is a professor and he and his two brothers are some of my best friends. He has a tremendous personality and is a total clown being the youngest of the three, but he's absolutely brilliant. So, he and his wife had a son and the oldest brother had a daughter who was a year or two older than his son. He and his wife were taking his brother's daughter home along with his own son one day. When they got to their car, they realized that his brother didn't leave a car seat for his niece, and that they only had one car seat. So, they put the niece in the car seat and his wife sat in the back and held his son.
Unfortunately, he was turning left and his wife and son were sitting on the left side and they were broadsided. His wife suffered several major injuries and his son was killed in the car crash. The crash was my friend's fault. He failed to yield the right of way. His niece was ok, save some scratches and bumps and bruises, because she was in his son's car seat. As was he. So who's at fault? My friend who I love like a brother, lost his son because 1) didn't have a car seat for his niece so they gave up the one they had for her and 2) he failed to yield the right of way.
Do you convict him?