The article you cite does not claim that the Navalny poisoning was a US/Saudi false flag. On the contrary,
Murry states:
"I should state that I have no difficulty at all with the notion that a powerful oligarch or an organ of the Russian state may have tried to assassinate Navalny".
The article states that "[T]he US and Saudi Arabia have every reason to instigate a split between Germany and Russia at this time." The US has gone out of the way to prevent the NordStream 2 pipeline, and directly after Navalny was flown to Germany, several high-ranking German politicians (including Merkel), have began publicly to question whether NordStream 2 should be reconsidered, in the light of Navalny, see [1].
May I gently request that you exercise more care when representing Murray's views? Please reconsider the HN guidelines for comments [2], reproduced here for your convenience: "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."