For consideration: the Empire most likely did not completely disintegrate as a result of the Ewoks killing some stormtroopers. That is, the Ewoks did not defeat the Empire.
They simply assisted the Rebels by providing a distraction. Watching the Battle of Endor, it was mainly Chewbacca that actually ended up routing the Imperial forces on the Forest Moon by capturing that AT-ST.
And anyway, look at how many Ewoks there were compared to the stormtroopers! That is why they were able to overcome them initially: they hid in the trees, and then attacked suddenly and en-masse, using their advantage of numbers and stealth. Most of the times, the stormtroopers simply couldn't get a shot off because the Ewoks weren't fighting fair. Sneaking up and attacking the stormies 3 to 1 was their MO, and it worked long enough to allow the heroes of the Rebellion to do their thing.
But had the Ewoks been attacking alone, they would have been destroyed, because they couldn't deal with those AT-STs. The Empire would have recovered from the initial surprise and pressed the assault into the forest, blowing stuff up indiscriminately. Or the Death Star would have just blown up the moon.
I'll answer this separately from my previous post, as I want to discuss the core point, and not the thing about the enterpretation of that phrase.
Like I've said earlier (and I think others agreed), if only they had shown the rebel forces doing... well... anything , after the Ewok attack, then sure, I'd buy it.
But they don't.
The Ewoks attack, and then they pretty much beat the entire Imperial legion by themselves.
Leia, Han, C-3PO and R2-D2 are by the bunker trying to break in (poorly).
Chewie is the only one we see taking part in the battle.
The rebel soldiers mysteriously vanish. The essentially play no more part in the battle.
So, like I said earlier, if they had filmed it so that you see the Ewoks attacking and distracting the Imps, then the Rebels clearing them out, I'd be ok with that.
The Ewoks clearing them out on their own, not so much.