A very good example of one of the potential concerns with calling out a specific member (and something that's actually happened here and pretty much in every online community). It's not so much high-schoolish behavior, as it is just plain human. We all want to be acknowledged -- in our presence, and yes, even in our absence. It's a basic human need shared by many.

If you're concerned about a specific member (who's also a friend), a PM is probably the best way to go to inquire about their health or what-not.