Looking at the original post:
"When I got home today, DH gave me a halfhearted hug and said hi, and then he went off to the bedroom. I waited a few minutes but he did not reappear, so I went to look for him and he was laying on the bed. He said he was tired. I tried to ask him about his day and he gave me grumpy one-word answers, so I decided to leave him alone."
I don't really see the issue. He went off to the bedroom to lay down and when you went to find him he said he was tired. The combination of the action and telling you he was tired sound like a clear signal to me, but apparently not. When you continued to ask about his day, he remained grumpy, but once he said he was tired, why press the point? Tired and not wanting to talk and not being able to do a repetitive task are very different. Sometimes tired doesn't mean go to sleep, but not interact with anyone.
I took our son outside to play and when I came in a few minutes later, DH was cleaning his gun (so I guess he wasn't *that* tired?) but he was still unwilling to converse with me. We left for dinner and we talked briefly in the car, although it's extremely hard to have a conversation in the car with our chatterbox toddler in the backseat. We did not get to talk at all during dinner
Just before he left for his xbox night, he asked what was wrong with me. I explained that his aloofness all evening had hurt my feelings. He said he was tired. I said "I know, but it still hurt my feelings that you grumped at me and ignored me." He repeated, "I. Was. Tired." I said okay, told him goodbye and said "I love you". He left without saying anything.
It sounds like you were then upset with him the rest of the night and he picked up on that and asked what was wrong. your answer of, "I know, but ..." can translate to, "I know you were tired, but I don't really care, I just wanted you to interact with me" whether or not that's how you meant it.
I think that the signal he sent, laying down, saying he was tired was clear, but I agree, he could have verbalized it better. I can see how you wanted more interaction, but on the other hand, if you are tired and just need some time alone, someone pressing is likely to not go over well.