R.J.
1) a friend clued me into the "stupid sixes".... Which was a huge relief. What it is: every single rule and standard of behavior you have ever taught (and that they mastered 4 years ago): gets forgotten & you have to reteach it. Every simple task they have ever been as to do ((putting on shoes, refilling toilet paper, (not peeing on the floor), putting their arms through sleeves, putting food in their mouths instead of dropping it, getting out of bed without taking the sheets off, using a tissue)) becomes this monumentally difficult task that they are seemingly convinced is actually impossible (or unfair). Your formerly chatty, inquisitive, and thoughtful child's speech degrades into the following 4.5 phrases: I can't, I did (when they didn't), It wasn't me, & I don't know. (Half phrase is staring at you, possiy drooling) as if they have NEVER heard what you're saying before, and may not actually understand it.
Oh, joy. Stupid Sixes.
Fortunately, its actually a sign of a cognitive emotional LEAP (wanted milestone). But its annoying and frustrating. Fortunately, its just a phase that passes. Patience, repetition, and consistency-consistency-consistency.
((7's are lovely, 8's are highly emotional mood swing lovebug/demonchild... Aka Crazy-8s, 9's are 9 going on 30 (or 16)).
2) Those things the other kid did may or may not have happened. Part of that cognitive emotional milestone includes lying. Mostly to see what happens, or in a 'what if' scenario, or to be able to tell the truth without getting in trouble (as in both were doing what he sai she was).
I'm not saying your kiddo IS lying, just that its reeeeeeeally common for kids this age to come to parents after the fact and talk about "WHY DIDN'T YOU GET ME???" types of stories. Some are very true (they wanted to handle on their own), some are partly true (it wasn't just their friend, or they were throwing things up, but what IF they were throwing stuff at the wall? And what if they were mean/angry about it? Or wouldn't listen when I said stop -when the friend did listen-, or what if, what if, what if variations on a true base), and some are pure fiction (how would mom react if this happened?)
Six is an interesting year.