This sounds like so much bullshit. Aside from it being physically impossible to add so much muscle in such a short time, here's a few things that jump right out as being obviously fake:

Suit size went from 40 short to 44 regular. The short and regular is the sleeve length. I'm not seeing how this changes regardless of how much muscle you put on.

The before photos look obviously bad, visible shadow. The after pictures look much better, better lighting.

No tan in the before pic but tan and hairless in the after. Bodybuilders do this to give the appearance of more muscle.

The distance from camera changes in the before pics. Gives the appearance of being smaller or it stretches him out so he looks skinnier.