It's interesting stats, but I don't know where they got their full stats. Just off the top of my head, Marques Colston has 54 catches for 869 yards, not 56 for 886. Drew Brees has 331 pass attempts if I remember right, not 344, and Bush has 53 catches for 352 yards, not 54 for 358.
The only thing I can think of is maybe they don't discount plays that are not counted due to penalties. But then looking over some other teams real quick, their numbers don't all match up either. Such as Andre Johnson is listed with 57 catches when he has 68.