Is it always safe to place a casualty in the Recovery Position ?
No. If you are concerned that there may be a spinal injury, then it may be that, if it IS avoidable, you do not place the casualty in the recovery position as long as you can stay with them and safely maintain an open airway. In cases such as this, you should avoid unnecessary movement of the neck and spine as much as possible. If our 'prime directive' is to maintain the open airway to maintain breathing, our 'secondary directive' should be to avoid inflicting further injury ! The video below explains this in more detail.
If the casualty stops breathing, however, then you have no option but to place the casualty in a position whereby you can perform effective CPR. Should breathing stop, death is imminent, and so we reach the point where the prime directive is the only directive ! In this case, though, you would try to quickly, but carefully, place the casualty in a position to work on them.