with hindsight you probably know what you should have done, and he probably knows what he should have done
ie: not wake his sister. But as these things happened, I think you just hug him and forget it and think through, talk through things in advance next time (but possibly not talk about it this time anymore). Maybe no noisy toys in car if you want her to sleep at that time, or maybe talk through to him how she is sleeping and you never wake sleeping children at naptime, unless instructed to, or they get angry and grumpy (this could be a general observation you could keep reinforcing every single day - social story etc, general rule, sleeping soft toys)
I think warnings tend to backfire in our house, as once the transgression happens there is nowhere to go, except an escalation. better to work on avoiding the thing happening in the first place in a more positive way. If you do that one more time I'll x...is setting yourself up for an explosion.
The fact that he normally would hit out and get cross shows that even normal isn't particularily satisfactory, so I would work on changing the whole vibe around him obeying instructions.
Essentially rules tend to work with ASD children if they are established rules which make sense to the child and make child feel good, whereas random instructions or what they consider unfair or uncomfortable never really hold any weight whatever the threat or warning.
btw, I've been through all this, I completely understand how you feel, and this is all with the benefit of hindsight. We've had many of the scenes you describe - please listen to zzzzz too, it is easy to overestimate the malice or intent behind a child's emotions. They are just that, a reaction, anxiety shame, fear. Fear that you hate him is more likely than him hating you.