TM is right, that approach may help. I would explain to the parents what happened and also try to involve husband in the apology. Eventually, at least.
Keep husband in the loop asmuch as you can, on the consequences of what has happened.
DHs who are not as connected with the day-t-day management of our kids (especially their social lives) tend to mentally snap back to how they did things when they were 11. And forget that was a long time ago, a different place, a different time, different attitudes. Life has changed and we have tighter standards by which we control our kids' play.
Example - difficult child 3 was invited by his best friend (also autistic, but milder) to go fishing on Good Friday, with a lot of friends. It was a group of 10 year old boys togeter, and one 15 year old. I KNEW there would be no adults along. The boys - most are nice kids, but a large enough group of boys can get into trouble so easily when there is no adult along, especially if acouple of them are a bit weird (ie difficult child 3 and his best friend). So I went along too. Not as chaperone - oh no. But the boys needed SOMEONE who could bait hooks, tie on lures and mind the rods when they gve up on fishing and decided to jump in for a swim instead.
Nothing went wrong. The boys were all good to one another, no unpleasantness, no real reason for me to be there.
Except - if I hadn't been there, would they have been so well-behaved? Maybe. But who knows? I played down my profile, I did my best to blend in, I tilted my hat back and pretended to snooze. But I was still there, just in case.
And I enjoyed myself, it was a relaxing place to be and I enjoyed watching the boys have fun. From the swearing that I heard (and did not correct) I suspected my "blend in" worked.
I was also there and able to hose things down when difficult child 3 got upset at not getting his lures back (MY lures, thank you!) when it was time to go. Those lures cost about 20c each, one was permanently part of the marine substrate, having got tangled in a mangrove root. Another was falling apart. I had no trouble with letting the boys keep the lures on their rods - what were WE going to do with them? We still had two and we can buy more in the local shop any time.
If I hadn't been there at that point, it could have gotten unpleasant due to difficult child 3. He needed a social guide at that point (I can't expect 10 year olds to have the maturity to handle him when he's upset).
Would your husband "get" this example?
Another thought - why not get your husband to do something like this with a group of boys (even if it's just Piglet and one friend)? If you can go too, then that would be good. But the more exposure husband has to the range of situations where his quiet guidance would be welcome, the better.
We all need to remember to involve our husbands more and to keep them involved in "refresher courses" in meeting the needs of their own kids. I realsie that for some of us, the phrase "kicking and screaming"comes to mind.
Whatever it takes.
Marg