Calvin Johnson also played bad in some other games.. The game against Troy State he was terrible . His name isn't even on the stat sheet for that one..
So I wouldn't go just by how he was against Calvin Johnson.. Remember Johnson had an atrocious QB throwing him the ball ..A good GM goes by the whole body of work over a player's career..
If an average WR had a good game against him, that can also be seen as a negative .. I'm not saying that happened because I didn't see all his game tapes, but let's not jump the gun here all because he had one good game against a terrible QB.