Is it normal for me to still be upset at my husband for this?

My husband is a VERY laid-back guy and nothing ever gets to him -- EXCEPT when he's tackling a plumbing problem. The other night, he was trying to fix the toilet and when it wasn't going well, he would either swear really loud or slam his fist or throw something. This is not like him, and it kind of scared me. While he was in this mood, he would snap at me or raise his voice at our one-month-old for not keeping his pacifier in his mouth. I spent the evening in the basement in an attempt to avoid him, and when he came down he could not get his head around why I was upset. He still doesn't "get it" and doesn't understand why I can't just forget about it. Do you think it's normal that I'm this upset? What do I say to him to lovingly let him know his behavior was immature and stupid?