Peter, your wife is right to keep track of what is going on, but speaking from experience, she shouldn't be automatically assuming the school has got it exactly right. You have an Aspie - they do tend to be truthful by nature. Yours is lying to you (and probably bad at it, which is how you know about it) because he is feeling constantly under threat of punishment and is desperate to avoid it. Kids lie to get out of trouble. If you can reduce his troubles (at least at home) then hopefully you should be able to reduce the lying (at home). He needs to be encouraged to talk about what happened, from his point of view. If you know him well you will be able to find the truth, somewhere between his face-saving responses and the teachers' doom and gloom.
Also, get wife to read the posts here. Tell her I said it will save her time and a great deal of energy. husband & I do this and it has strengthened our already very strong communication. We don't always agree with everything here, but it gives us scope to discuss it. A lot of what I have learnt here is counter-intuitive, but it is working so much better for us!
There can be advantages to having an Aspie child, but he needs to feel safer than he does right now. You and your wife know him much better than the teachers.
With my boys, it was sadly a common occurrence for the teachers to make things worse and yes, to make false accusations (because they never got to the truth of the matter, but took the easy option). We had spies in the classrooms and playgrounds, from them and the teachers, and from difficult children, we worked out what the truth really was. We confronted the staff with it who just shrugged and said, "Does it make any difference?"
Not all teachers are like this, but unfortunately some are. And we had 'em.
I suspect your son is having a really awful time at school but doesn't feel safe enough to tell you. I also found that difficult child 3 would self-censor and forget the really unpleasant stuff. When he began to say, "I don't remember what happened after that," I really began to worry, especially if he had bruises. Sometimes if I collected him from school and I hadn't been seen arriving, I would hear what was going on, and it was interesting to tally that with what I was being told.
difficult child 3's teacher accused him of lying. difficult child 3 had bloodied knees and had told the teacher that a group of boys had tripped him up. The boys told the teacher that difficult child 3 had tripped over his own feet. difficult child 3's friend quietly told me that he HAD been deliberately tripped, but the teacher didn't believe him - there were six bullies, vs just the two (difficult child 3 and his friend). So the teacher chose to believe the larger number, even though they had reputations as thugs.
Later, difficult child 3 punched the head bully. The teacher saw him. "Did you punch J?" he asked.
"No," said difficult child 3.
That time, he WAS lying but it wasn't a complex lie, it was a lie of denial. We found that if we asked difficult child 3 to explain a situation in detail, THAT is when we got truth, even if he'd been lying before. He's just not fast enough or capable enough of inventing a really complex alternate story; for him, the truth always finds a way out even if he's trying to lie. As a result, he's learnt to not bother, I'll always catch him out. I also didn't punish at home for what happened at school. The school event was often punishment enough. At home I would get the story from him, try to work out what really happened (because sometimes he was telling the truth, but from his point of view, he would think someone had pushed him deliberately when they had only jostled him accidentally). Then we would role-play it, to try to find a better way he could have handled the situation. If appropriate, I would get him to write a letter of apology. But never anything more. Certainly no loss of privileges, no grounding, unless I felt he needed it for his own safety (such as keeping him home when he was a constant bully magnet every time he went for a walk).
Any punishments need to be appropriate and immediate. Schools don't always do this.
We went through this with difficult child 1 as well. His best friend (also Aspie) - same story. Very frustrating, but the pattern seems to be one of trouble, often with the kid nowhere near as 'bad' as they're painted by the school.
Not an easy situation, but you and your wife need to be on the same page.
Tell her I said hi. So does husband.
Marg