Been there, done that...don't be an aye hol to them.....just go back out and work the methods like the above mentioned.
This is what you need to do.
Use handrail, in and out, they will watch from a distance.
When you pull up to a stop, don't grab your bag of cheetos, just shut truck off and open door, enter cargo area and get boxes, place in cab, close bulkhead, exit truck, reach back and retrieve boxes or load cart.
Repeat this step about 150 times or more so when the supervisor that followed you all day can only report back that you were following the methods.
Every time without fail: Stop at all stop signs, use your turn signal, tap horn when backing.
Don't let them intimidate you and don't go out and lay down.
They know you're over dispatched, it's the "stops per car" flavor right now.
If they mention anything again, get a steward.