Does Masterchef Australia manipulate or fix results?

As I get ready to watch the best contestant in the game this year, Matt, possibly go home with today’s elimination test. I wonder. 
Does Masterchef have some reality TV manipulation going on? After watching Unreal, a dramedy about a show like the Bachelor. written by ex writers from the Bachelor, and reading articles about how dishonest these reality TV shows results often are. It makes me wonder about MasterChef Australia. 

When a mediocre cook like actress Theresa Wong Visintin, gets back in midway, after having a few weeks off to memorize the dish she cooked and learned from former Masterchef dessert star, Reynold Poh, that makes me question this show.

Then having her back in the game, and blowing the relay challenge. Since she cannot ever think of a good dish on her own, since she is a recipe follower, not a chef, causes her team to lose. Poor Anastasia, who oddly gave her the power apron advantage of the choice of using any ingredient, which was, hmmm surprise surprise , coconut, an ingrediant that she must have to make the Reynold Poh dessert? How did that all happen?

When were her and Anastasia ever shown to be close on this show? They never showed that. I thought that was very odd. Then after that, which in no way benefited Anastasia, she had to give Theresa the apron? The whole thing stunk to high heaven of manipulation by the show.

How honest is this show?

Also why is there not mention of Theresa Wong being a career actress anywhere on the MasterChef website, in her profile or on the show?
It is what she has done for years and continues to do. Her IMDB profile shows work right up to now.
http://www.imdb.com/name/nm0939358/

Also she lives in Canada, was born in Singapore. How does she qualify for MasterChef Australia? Or her brother, who also was born in Singapore and lives there now? This really bugs me. No where online could I find how long she ever lived in Australia. She NEVER talks about Australia. Which is odd, since everyone else does in all their stories. Probably since she did not grow up there, she has no ties or culinary memories of Australia.

Here is her actress show reel.

Theresa Wong Showreel from Theresa Visintin / Wong (2) on Vimeo.