(HSA/Auto Vehicle Hold) Upon backing out of a heated garage onto a flat, lightly snow-covered asphalt driveway, a light to medium brake apply to test out surface conditions was done, and little to no sliding was observed. Upon reaching a conclusion that it was likely safe to proceed, vehicle was shifted into reverse and upon nearing the crest of a 14% grade on a residential driveway (asphalt), brakes were lightly applied (similar pedal force to the "test"), then released once grade was almost crested. The vehicle had been shifted into neutral and clutch was released prior to applying the brakes. It seemed as if the brake pressure from the light apply was not released, and wheels remained locked causing loss of control. ABS did not activate, and steering input had little/no effect. Vehicle slid off of driving surface and struck a tree, causing damage to rear bumper, tailgate, and rear left quarter panel (no visible frame damage). Upon safely bringing the vehicle back onto the driveway surface (bottom of driveway, ~5-9% grade), a second test to see if brake pressure was trapped was performed. The vehicle was allowed to roll to ~3mph, same light pedal force as before was applied and the brake pedal was released (in neutral with clutch released). The vehicle skidded to a stop with no signs of ABS or stability control activation (no lamps, etc), and about 2s later, a clicking sound was heard from the engine bay and the vehicle began rolling freely again with foot still off the pe