Typically if it goes in from one side and hits the opposite shoulder the arrow would stay in and or snap off leaving the fletching behind. That’s a pass through. Mechanical heads aren’t known for staying intact with a shoulder hit.
OK. I myself would look at where he was vs what direction he was headed. Find Creeks, Thickets and anything a deer could lay down in. All you can do is grid search for the deer and hope for the best. Friends will help you cover more ground.....