Megan, this is a good place to vent!! It is not really a little thing because you miss spending time with him and often we feel what they do is a deliberate action against us BUT usually it really is not!! Their minds as you seem to already know are in a very different place than ours are!! I just got a very interesting email from a new "friend" who has been married to a Vietnam Combat Vet with PTSD for nearly 44 years!! She describes us as the stable half of the relationship and how dealing with them and their PTSD can really burn us out at times and how very important it is for us to take care of ourselves first and foremost as without that we can not be any good for them!! They really do truly care about us or they would not be with us and they certainly do need us because we are their main link to what should be a normal life!!
Although, others may say if it really bothers you, you should tell him, I think you should mention it lightly BUT to push the issue only will result in an argument and him getting into a "funk"!!
As you say, in the grand scheme of things, it really is not that big BUT nonetheless I truly do understand your feelings!! I can't help but feel that it is the uncertainty as to whether it is a deliberate act or not is what is bothering you most and although I or no one else has a crystal ball, I tend to believe that it is not or there would be a lot of other things and he would not still be with you!!
All this probably did not help you much BUT you seem to be pretty well informed about PTSD and that knowledge will definitely take you a long way!! Keep searching for more and more knowledge because I firmly believe that is the key to understanding!!
I recently was told about a book by the woman I got the email from which I intend to get and if it turns to be even half as good as she claims it is I will definitely let you know about it!! I am not one to recommend a book to anyone without first reading it myself!!
I wish you well and never feel bad about venting here as that is not only good for you BUT also for him as it often takes some of the edge off everyday life!!