I don't know if he was specifically was on SARMS. But, that class of drugs was the one mentioned to me. Pretty prevalent in D2 and NAIA. A SARMs test is fairly expensive at $400-500 a test and you need a specific test to detect them. Even so, some SARMs can be undetectable after 5-14 days, so you time it right, you won't get caught - the guys know the general timelines of when NCAA tests.
The following is hearsay, so I don't know the accuracy.
D2 and NAIA don't test because of the expense. Hell, they hardly test as is. I know Championship game they test around 10% of the guys at random and during winter conditioning/spring ball every team has around 10% tested.
D1 will only test for SARMs at random of the test they do complete.