They didn't test him because it's not a real experience. It's only fantasy.
In basic training, it's all about numbers. If you made it though MEPS, and get to basic training, you will graduate barring extreme injury or death, or they'd have to catch you in the act of doing something, like smoking crack in the bathroom. It would have to be something totally absurd. No one will go through the trouble to test some new soldier etc for steroids. It's only downsides, zero upsides, for everyone, from the instructors, to the commanders, all the way up the chain of command, and the unit itself. No one in the command would approve it. They'd have to find actual steroids on you in basic training and then they wouldn't even test you. They'd chapter you and you'd be gone. But it's impossible to bring anything like that with you. Impossible. Forget it. This guy 4Drago is making it up.
It's a fantasy. "Oh look at me, I was so jacked, my instructors were so amazed that they wanted to test me, and I volunteered to do it!". Sure buddy. You don't have a choice to volunteer. It's not a negotiation. If they want to test you, they tell you to go piss, without discussion. But they wouldn't do this anyway. So enough.