It's quite possible, one of the main versions actually. But this version is inconvenient for Russian state, because it automatically implies state cooperation:

According to Flightradar24, the aircraft reached an altitude of 28,000 feet before falling. Many air-defense systems are incapable of hitting planes at this height. For example, the shot would have been virtually impossible for someone on the ground (such as Ukrainian special forces) using a man-portable air-defense system. In fact, any kind of short-range air-defense missile system likely could not have reached a target so high. At a minimum, this would have required a medium-range system (such as a Buk) that was also located near the target plane’s air path.