It could be.
It also may not be.
I supported ExDP through the diagnostic process. It was a true minefield at times however the way I were treated was instrumental in the diagnosis and the reason DP decided to pursue one.
The selfishness, self focus-I am not saying that autistic people are selfish on purpose, but the fact that 'aut' literally means 'self', is a nod toward the fact that a lot of people with ASD assume their way to be the right way, their needs to be what matters, finding it difficult to consider that someone else's needs are important and valid, and that they're even more important sometimes in certain situations.
Again I am not saying every single person with ASD is like this, or that it isn't a product of a genuine disability. I am not saying people with ASD are horrible and evil or anything such as.
Selfishness e.g. I liked to talk on the phone and DP didn't-DP's need was met, absolutely not a chance we could have a phone conversation because 'I don't like it' 'I don't want to'. There were some exceptions, the main one being I was allowed to ring when DP was at work and alone. Not at home, not with friends-and very rarely was anything else the case!
I got an absolutely baffled look when I said something like 'but I'd really like to talk to you tonight/after my medical appointment/when I come back from being away'-it was unfathomable that I'd want that or that I'd ask that question because I should know it absolutely wasn't happening-'I don't want to!? What has the fact that you want to got to do with me?!'
Special interest fixation-it was me, but then it became a new hobby. Someone without ASD would usually know that a new hobby doesn't mean you forget about someone important to you, it wouldn't be even a question. From DP I got 'Well what am I meant to do? I like doing (hobby)!?' when I suggested that perhaps I'd like to spend time together at a time hobby was on (we only saw one another at weekends so doing both separately was not possible & because of special interest fixation, absolutely no chance of choosing 'us' or me above it).
Unable to integrate me into the hobby meet-ups. I was happy to go even though It's not my thing and again, I had a choice to either not spend time together at all, or go along to these meet-ups. But DP couldn't cope with having me there, again, this can be ASD. In an ASD mind, those things were separate. Being with a girlfriend AND being a hobby-goer and part of that group, at the same time, was too stressful for someone with ASD. Hence being horrible to me while I were there. Ignoring, bullying, snidy comments-I wasn't 'meant' to be there (despite being invited), it was too much to cope with and a mini-meltdown ensued-not a 'storming off' or crying or shouting one, but becoming annoyed and irritated and jibing at me helped.
Of the party, someone with ASD can assume others know what's occurring, because they do.
DP knew where I were and what was happening, and was tired, so going to bed seemed a perfectly reasonable thing to do.
Wouldn't have ever thought about me, in a strange town with strange people (to me) alone after travelling to spend time together. How I felt wouldn't enter the mind. The lack of that sort of emotional connection dictates that sometimes, someone with ASD will never feel that way. I was so, so upset and met with absolutely no understanding as to why.
'You seemed happy enough'
'I wanted to go to bed'
'I knew you were safe, so and so and so and so were there!'
DP hadn't done this to hurt me. There was a lot of upset once it was made obvious that I was upset, but in DP's eyes, the leaving of a long-distance partner to go home and go to bed was fine, because I was okay, and 'I wanted to go to bed!'
The fastidiousness was nothing in comparison to the above an a thousand other examples I could give, but illustrative of ASD. Meticulous hygiene, I 'wasn't allowed' to cook because I might (for example) use an ingredient I've had in the cupboard for a while. God forbid I went out in a scruffy jumper even if just to walk the dog, it was unfathomable to do that. Clothes for each occasion must be new. Having a container without a lid, in the fridge is disgusting! Sensory issues with fabrics, food and other items.
Unable to handle upset of any sort. Hence ignoring me when I was upset-about a medical examination that could've had a serious result. It would be too much, and (again, I apologise but I can put this down to ASD) meltdown ensued, couldn't cope with the situation-so shut off from me.
I sought support from friends instead.
Of course, it could also be put down to my ex DP just being an arsehole. But most if not all, of the things that happened, I can unfortunately put down to ASD traits and characteristics.
I do not want to derail the thread and make it about me, but nor will I not give examples that OP has asked for and the point I am trying to put across is, a lot of if not most of it, wasn't because my DP was trying to be a bad partner or to cause me pain.