I have been wrong. Setting pos and hpr on the motion node doesn’t work, because I left away the PandaNode hooks. This is one reason why I want to make BulletRigidBody a PandaNode and remove BulletMotionNode.
So far you can change the body’s position by using BulletRigidBody.translate(…). A method for changing the orientation is missing so far. I have added BulletRigidBody.setHrp(h, p, r) in the following release (no other changes, but using current Bullet version r2233):