May be he is really tired (because of his job) and cannot afford to lose some sleep.
There is really no need to change the diaper at night. This is such a tiring job for parent. And it is not good for baby too. There is no need to make everything perfectly comfortable. A wet diaper is not going to make him sick. He has to put up with a wet diaper. In fact, this is a good training.
I think there is no need to be too upset. My husband did not change my second child's diaper for once. I know, this sounds horrible, right. But this is just his personality. He is always there for everything, but just not the diapers. I think I can let him go for that.
Now my children are big and they are all close to dad. Dad is the best in basically everyway. The only "poor" thing is the diaper, otherwise, I would say he is a perfect dad.
Sometimes, we have to let go of certain things when we look at our other halves.
most men think changing diaper is womans job!! if he woke up and think its abt time to change it, why he dosent do it by himself intead of waking one more people up! slefish man