How to verify that test results (unit or integration tests) are not falsified

The Question:

How do we test that the automatic testing machine is performing as intended and that it's not spitting out fake reports?

Thoughts

My best guess at the time:

Picking a couple of suites, on a random, and reading them should review false play

Or if machine has to do it, maybe view the total length of all tests, run some inspections for copy pasted code, checkout git tags in the past and see that the tests are changing, that an existing test is modified, that is a sure tell, nobody making fake tests will return to modify a perfectly working fake

Now that I think of it, maybe they were interested to verify that the environment running the tests was not returning forged results, marking the tests cases as successes even when they should fail

Any thoughts?

Tools for fake tests

I remember I've stumbled once to a test faking tool: http://ift.tt/1Om8Txh, took me a while to find it again (in a chat)

PS

I can't find anything on the topic on google or stackoverflow, it seems that when you combine test and fake the results are always about mocking and stubbing.