With the NFL's new focus on concussions and injuries....can someone help explain please..?

Maybe I am mistaken, I forget the order of lots of things but - I could have sworn we saw L Jack get hurt - he looked knocked out to me -only to come back and get a sack.  Now he's listed as out with a concussion.  Did that happen after the sack on a subsequent play?  

Also, for what it's worth - I think we have to give Schwartz more time - I don't know why more experts aren't being called out on supporting most of Millen's moves (many people projected Mike Williams as a top pick and he "fell" to Detroit) and you can really tell which announcers have watched the Lions games this season, and which ones have only read the headlines.

Happy Thanksgiving - Being out of the Lions' market,this used to be the one game of the year I was guaranteed to see.  Go Lions