being that the steer motor keeps running even when the key is turned off makes me think there is something more going on here besides steering ring's.

When the key is turned off it should De-energise the line/power contactor or relay and disable all electronics, even the power steering. If there is no contactor that controls this then there must be a relay or pressure sensor controlling this somewhere on the truck.

All electric trucks i've dealt with have a contactor or relay that controls the trucks power. The truck should not do a thing without first activating this.
My guess is you have a stuck contact holding the power source 'ON' allowing the steering circuit to stay on.