“Good thing the Ukrainians left a major arms stockpile unlocked and unguarded for them then, right?”
Pretty much, that is exactly what happened. Google it, there are many articles about it from March.
Also, don’t forget the the Slavyansk group also got the weapons and APC’s of a Ukrainian Airborne Brigade that surrendered to the Rebels, including a TOW APC, an AA Missile APC, and a Truck-Mounted AA Gun.
Not a Brigade, a company. OOPS...