There are many people who do this. It does not help. In fact blaming and anger makes the situation worse, hurts your husband, your child and yourself. Since you're aware that you get angry and blame you can stop doing it. Instead of telling yourself it's his fault or he should've done something different, stop yourself and say, it was just an accident. I will remain calm. Then don't say anything until you are calm and able to talk without blaming him.
After your addition. Yes, it's usual to get upset when it looks like the person should've been more aware and prevented the accident. It's still important to calm down before saying anything. When we approach someone in anger, they either don't hear us because they tune us out or they react in anger and miss the point. If you want your husband to be more attentive you need to talk with him in a respectful, understanding manner. "yes, dear, I know you were watching TV. Could you please look up and pay more attention so this doesn't happen again. Look at his poor little bottom. I know you don't want him to get hurt. etc.
I suggest we flip because on some level we have convinced ourselves that we wouldn't have let that happen. Our anger protects us from seeing that we're also less than perfect.