This appears to be a credible story.
As reported by Liz Sly for the Washington Post:
Russian soldiers have attacked and injured their commanding officer after their brigade suffered heavy losses in the fighting outside the capital, Kyiv, according to a Western official and a Ukrainian journalist.
Troops with the 37th Motor Rifle Brigade ran a tank into Col. Yuri Medvedev, injuring both his legs, after their unit lost almost half its men, according to a Facebook post by Ukrainian journalist Roman Tsymbaliuk. The post said the colonel had been hospitalized.
Tsymbaliuk is the Moscow correspondent for the Ukrainian News agency UNIAN. The incident occurred two weeks ago. According to Sly’s reporting, the brigade in question was reportedly engaged in operations in and around Makariv, a town west of Kyiv that Ukrainian forces are now believed to have recaptured in their push to reverse Russian territorial advances. According to Tsymbaliuk’s Facebook post, the 1500-man brigade had lost about half its strength in combat, either killed or wounded, prompting a soldier to run over Medvedev with the tank at a “convenient moment” during the fighting.
There is conflicting information about Col. Medvedev’s ultimate fate. Tsymbaliuk’s original post indicated he was hospitalized in Belarus awaiting “financial compensation,” presumably from Mother Russia. Metro UK and the Daily Mail published video and still shots (purportedly released by Chechen authorities) of Medvedev being packaged up on a stretcher and transported to a Belarus hospital; at that time Medvedev was described by Russian sources as being wounded in battle. The Daily Mail article, for its part, indicates that Medvedev had since died (which correlates with the unidentified “Western official’s” assessment, cited in the Post article.).
The episode has echoes of 'Fragging' during the Vietnam War - when soldiers would take out hated officers by throwing grenades into their tents.
As Sly reports, the incident reflects the “plummeting morale” of Russian troops in Ukraine.