As
@Kieran says, it was 90 minutes before the match, not 60 minutes, but it's reasonable to assume that was within his "match prep" time. The tester wasn't "late." I've been looking into the rules, (which are not easy to discern,) and there are a couple of things, and some vagaries. There is no requirement to advise ahead of time that there will be a test. In fact, the rules state that, except in extraordinary circumstances, the player will not be advised ahead of time. There are subject to testing from the day before the "event" begins, and until it ends, in the case of a team event, which this was.
What Novak objected to, it seems, was the close proximity to the start of the match. And if Novak acted angrily, well, he is #1. The rules are clear on refusing a test, but not on putting one off until after the match. It also says that the player, with good reason, may put off a test. It could be deemed that he had good reason.
Now, we know that doping methods change, and often ahead of the rules, so, if it is true that banned substances can deteriorate in the body during the match, then the rules should be changed. Not saying that Novak is guilty of anything, just discussing what's on the table right now.