I think most folks here understand this was an event brought on by numerous "failures" by multiple people in an environment where safety was, to say the least, laxed.
However Baldwin, as the person using the gun and the last person to handle the gun, does bear a greater degree of responsibility in that chain. This notion is in accordance with basic principles of gun safety as understood by range masters, gunsmiths, competition shooters, amateur shooters, hunters, Olympic shooters, parents teaching their children and Hollywood actors who handle prop guns. You always handle a gun as if it was loaded and understand you are ultimately responsible for whatever comes out of that barrel. The four universal (and immutable) rules of gun safety have no exception for any circumstance. Everybody who learns to shoot can recite them.
To someone who doesn't shoot they might wonder, what is the purpose of having staff check the firearm in the first place if you are going to do a thorough check yourself in the end anyway? The baked in rationale accepts and accounts for human error. It is inevitable that someone on a bad day would have a lapse in judgement or get careless. When that happens, it is beneficial to have multiple failsafes.
I'm a doctor. Back when I used to do inpatient medicine I would always have to check compatibility of a unit of blood before transfusing a patient (In fact there would also be at least one nurse checking it simultaneously with me and we would read the information on the label out loud together). Another nurse who handled it before I did would have also checked the unit when they received it. Before her, the blood bank who received the order in the first place would also have checked. Of all those people I, as the physician administering the unit, would be the last person in that chain.
If I ever ended up transfusing a unit of incompatible red blood cells to a patient, it is understood that I would be the main one responsible. I couldn't fall back on blaming the nurse or the blood bank before me when I was the last person in that chain.