When you’ve had as many drug related issues/suspensions as Gregory has had, you only miss a test for one reason and we all know that reason. Don’t tell me he forgot or just didn’t have the time. If he was truly clean there’s no way he’d miss a test unless he’s stupid beyond belief.
With all of the players that get tested, probability dictates that some missed tests actually were due to reasons other than because they expected to fail the test.
It might not be a large percentage that "legitimately" missed a test but it definitely can happen, especially during the off-season when players don't have the weekly team structure.
Once we consider that it is possible to unintentionally miss a test, then the punishment for missing a test is the next discussion point.
The missed test is generally treated as a failed test because obviously if the punishment is less for missing a test then players will always skip out instead of failing.
Having said that, hopefully for players in the program that are tested often get some margin for error such as being allowed to miss 1 of 10 or something like that.
Even the exception to allow missing 1 in 10 does not mean they get zero punishment for the missed test, but another suspension would be excessive if a player missed 1 test out of 10 or more.