Looks like they left behind a shocking amount of supplies and equipment. Lots of tanks, self-propelled artillery, BMP's, and ammo appears to have been left behind in the mad rush to get away. Also, it appears alot of soldiers and equipment got captured because the Russians were not getting orders quick enough to react to the ridiculously fast pace of the changing battlefield landscape. They just got caught paralyzed---afraid to move without orders---and then panic set in when they realized the Ukrainians were already nearby---or even behind them.