The only calls I really thought were awful were the blatant pass interference non-calls, and the horrible OPI called when the replay showed it should have been DPI in the EZ.
Switz ... come on now.
Doug, the DB was pushing the WR backwards, you can't do that.

If you mean the DB was "posting up" and using his back and butt to "clear out" the WR ... I think that's for all intents & purposes "legal" so long as the DB is looking at the ball and isn't using his hands to grab jersey or push off. Never seen that kind of defense called a PI without some handwork being involved.
From the
NFL's Digest of Rules (my comments in red):
Actions that constitute defensive pass interference include but are not limited to:
(a) Contact by a defender who is not playing the ball and such contact restricts the receiver’s opportunity to make the catch.
Greer was playing the ball and was entitled to his position.
(b) Playing through the back of a receiver in an attempt to make a play on the ball.
Nope
© Grabbing a receiver’s arm(s) in such a manner that restricts his opportunity to catch a pass.
Nope
(d) Extending an arm across the body of a receiver thus restricting his ability to catch a pass, regardless of whether the defender is playing the ball.
Nope -- Greer was in front
(e) Cutting off the path of a receiver by making contact with him without playing the ball.
Greer was playing the ball
(f) Hooking a receiver in an attempt to get to the ball in such a manner that it causes the receiver’s body to turn prior to the ball arriving.
Nope
Actions that do not constitute pass interference include but are not limited to:
(a) Incidental contact by a defender’s hands, arms, or body when both players are competing for the ball, or neither player is looking for the ball. If there is any question whether contact is incidental, the ruling shall be no interference.
This case most closely describes the Greer play, IMHO.
(b) Inadvertent tangling of feet when both players are playing the ball or neither player is playing the ball.
Nope
© Contact that would normally be considered pass interference, but the pass is clearly uncatchable by the involved players.
Nope
(d) Laying a hand on a receiver that does not restrict the receiver in an attempt to make a play on the ball.
N/A
(e) Contact by a defender who has gained position on a receiver in an attempt to catch the ball.
This may have come into play, too