The troops aren’t pulling anyway. There is a video on YouTube from the rebel side. The idea is that on agreed day and time both sides are firing a white flare signaling their readiness and leave positions. Important point is the presence of OSCE blue helmets. At agreed time rebels are firing their flare and nothing happens. A rebel commander radios Ukie side and they say they didn’t see it. He said I say you I hired the flare. They say we didn’t see. Rebels fire another flare and situation repeats. Then rebels find English translator and ask OSCE guy to radio blue helmet on Ukrainian side to say flare is fired. He tries but they “have situation” on the other side. That is how Minsk agreement works. And it is allegedly Russian fault.
Seems to me it's the fault of whoever isn't in control of the Ukraine military or some units of the Ukraine military. At this point, after the musical chairs at Army HQ in Kiev, it's hard to tell who can actually give the Army an order and expect to have it obeyed.