How does the test in Devs prove the multiverse theory?

Which test is that? Two scenes spring to mind.

There is one in which Lyndon teeters on the edge of a dam. There is a 50-50 chance of him falling off and dying and I think the theory is that in a multiverse his/her consciousness would switch to the alternate reality in which he/she survives. It's related in a way that I don't understand to the Strong Anthropic Principle which can be used to crack strong encryption... link a random number generator to a doomsday weapon in a way that the doomsday weapon explodes if the RNG doesn't guess the correct key.

There is also a scene in which Lyndon uses the multiverse-theory to improve the audio-retrieval of a scene in the past by gathering information across alternate pasts. Forest sacks him on the spot because Forest wants to recreate his personal past digitally as a virtual world, not an amalgam of possible pasts.