You have to treat each case on its own merits, or lack of them. The scenarios mentioned all have different qualities to them, so it's no use trying to compare.
Murray already said something along the lines of Cilic being stupid to not do the proper checks on his supplements. If it happened again, then I expect him to be more scathing.
In this particular scenario, I have less sympathy for the top players, because they should know better, and they have their own people who can give them advice, and they can afford to get their supplements checked, and to buy an expensive brand with all of the right certificates. There is a helpline available to all players, so don't have much of an excuse either, especially these days with everyone having the internet and knowing that it can be a problem.
Actively calling another player a cheat is a different matter. You have to be sure you are right, and there's just so much evidence against Odesnik, from a variety of sources. His supplements were contaminated in a worse way than Cilic's were, and Cilic manage to cobble together a plausible story, which fitted with his blood and urine test results, and not just the one that failed.
It's true, it's easier to call out a lower ranked player who you already didn't much like. Equally, if a top player was found to fail a test, it could look like poor sportsmanship for his rivals to make a show of it. You'd have to find a way to condemn the actions, without it looking like making excuses for the times he beat you.
At this point in time, I'm more bothered by Djokovic failing to fully condemn Odesnik, especially as he had plenty of time to think about it, and likes to present himself as a leader and stateman. I understand the desire to show compassion, but Odesnik hasn't actually said sorry, nor taken any responsibility for what happened.
It's all very well wanting to show solidarity for your countryman, and even to say you believe their version of events. IMO, he over-stepped the mark with some of his criticisms of the doping authorities in the Troicki case, and now his comments might be construed as suggesting Odesnik is a victim of a corrupt/incompetent testing system. It's incredibly unhelpful.