I have to laugh a little bit because I can hear my DD4 saying exactly that. Not in a mean way, just in a matter of fact way. She likes to get right to the point.

Yep, that's DS4!
I just try to remind both of my kids to not say things that might hurt someone else's feelings, there is always new things to learn, and one person can't know everything.
I think our problem is not that DS says things to other kids. We have had talks in the past about how he thinks/learns differently, and he's always been pretty good about other kids. But I think his problem is with authority!