I think it is possible to facilitate a bad sleeping patern. If a child learns that when they wake their parent comes and takes them back to another bed to sleep, with them, then that child will not learn to settle himself.
It's not a criticims, sometimes as parents we do what works for a quiet life, esp in the middle of the night, and before we realize it it's too late and we've cultivated bad habbits in our dc. But you do need to tackle it.
Your ds needs to learn that nighttime is time for sleeping, so be calm but firm - if he gets up just put him back to bed and say "it's night time now, go to sleep," and leave the room. If he persists carry on, but the second time you put him to bed just say sleep time, and the third and following times say nothing. And each time you put him back to bed, leave the room. If after five minutes he's still crying go back in and repeat the process, but don't make eye contact, don't turn on the lights and don't give any encouragement. It may take a couple of nights but it works. Oh and this should apply to bedtime routine too, not just for if your ds wakes in the night.
And broken sleep is a killer for anyone, but some people react differently to broken sleep than others, so while your dh is being harsh, I would try to be a bit sympathetic, and sit down and have a talk about resolving your ds' sleep issues when you are both awake and not miserable from the night before, and do it with a view to tackling things together, so maybe your dh can do the bedtime routine, and you can do the nighttime if he wakes.