That report claims that the pro-Moscow Chechen authorities received warning of the planned assassination attempt from an informer infiltrated into the insurgency ranks. The two fighters were reportedly shadowed from the moment they "came out of the forest" until they reached Grozny, where they were intercepted and killed in a gunfight by five Chechen police under the command of Kurchaloi district police chief Khamzat Edilgiriyev.
All of those statements are questionable. First, assuming such an operation to kill Kadyrov was indeed planned, it would have been kept secret from all except a very small number of senior commanders; it would not have been common knowledge.
Second, if the pro-Moscow Chechen leadership indeed has a "mole" within the insurgency ranks who is close enough to Umarov to know top-secret plans, why has that informant not communicated Umarov's whereabouts to his superiors to enable them to capture or kill him?
Third, Edilgiriyev contradicts himself. First he says the "mole" informed his superiors that the two men's assignment was to perpetrate a terrorist attack targeting Kadyrov. Then he claims that it only became clear after the two men were being shadowed that they were planning to stage a terrorist act.
Fourth, two fighters is almost certainly too few to get close enough to Kadyrov to kill him, bearing in mind the large-scale security precautions he always takes. At least one, possibly more fighters would be needed to create a diversion (as during the three-man attack on the Chechen parliament in October 2010), plus two or three more to ensure that at least one of them got close enough to Kadyrov to detonate explosives that would kill them both.
Five, by the same token, five police officers is too few to be certain of neutralizing two seasoned fighters. Six years ago this weekend, hundreds of Russian troops and Chechen police were deployed in an operation that lasted several hours to kill then-Chechen Republic Ichkeria President Abdul-Khalim Sadulayev.
In fact, the only point in the entire account that rings true is that Umarov has come to the conclusion that without killing Kadyrov, no other attacks or assassinations would have any effect on the situation in Chechnya.
A more plausible scenario is that the Kurchaloi police intercepted two insurgents by chance, killed them in a routine shoot-out, and took advantage of the opportunity to circulate a fictional account of the operation that would demonstrate, on the one hand, their own vigilance and on the other, Umarov's incompetence as a military commander.