I think the Captain was responsible for the deaths if it was a handling issue.
Do you have any proof that Mr Lebadev was either aware or sanctioned flights operating outside the aircraft operation manuals.
Owners employ people who should have the knowledge to operate within standard and accepted procedures.
This will be either a tech issue mis handled or a manual handing error in my view. One thing I do remember was there were forecast strong crosswinds at VKO that day, always an attention getter on a snow risk airport and SVO won't take you if you feel the need to go somewhere with a more into wind runway.