Sidey caused the Force try by not trusting his inside man. Sidey standing too far in meant that his winger had to follow him, causing the overlap. The Force shifted the ball very very well to exploit Sidey's mistake.
I'd vote Pyle's, personally, followed by Mafi.
The Brumbies' try was the result of good pressure, but it still took a lucky deflection and poor/lazy Reds cover. Kicks like that are generally a lottery, but on an advantage can be a good choice. Both of the other tries were better constructed.