I agree. We should be defending our priests and as I said in my first response, we don’t know why when the priest answered the OP he seemed to roll his eyes or seemed rude. We don’t always know what is going on in one’s mind or what they might be dealing with at the moment. He didn’t know what the plans were between the priest and the deacon. Maybe the deacon was told to leave the key there, maybe not. We don’t know.
It just seems some of the replies are a little off, suggesting he get counsel, because he saw something he perceives as wrong means he doesn’t like the parish,

, to having a psychological disorder characterized by guilt, undermining the priest, accusing the priest of sinning and not understanding what the words “I know” mean. None of which were in his OP.
I will agree no one should ever take the key and mail it to the bishop and as I said we don’t know why the key was left there. Taking the key is like two wrongs not making a right and none of us were there to see exactly how the deacon handled the hosts, so we can only go by what he is telling us. Maybe the deacon was in a hurry and it appeared as if he was throwing them in, or dropping them in, maybe he was being disrespectful. We are all sinners and the deacon didn’t mean to be disrespectful at the moment but might have been late and in a hurry. Also, he did say in his original post that after he told the priest he felt under the obedience of the priest and did was he was told.
He then asked another priest and was given a different answer as to what he should have done, so he is just looking to his fellow Catholic christians to get an idea of how they would have handled it.
Perhaps he was overly concerned and yes, absolutely, definitely we need to and always should defend our priest. I am all for that and I am not sure if I would write a letter to the bishop but I guess I just see him asking a what would you do question and getting some “I am reading more into this” responses.