Gutierrez-Reed's attorneys Jason Bowles and Robert Gorence appeared Wednesday on "Today" to outline their "sabotage" theory, and went so far as to consider potential would-be culprits.

They revealed the person who could have slipped in the live bullet would have had access and opportunity to do so between 11 AM and 1 PM ... when the ammunition was left unattended outside on a tray.

They also say Hannah wasn't even in the church during the incident because it wasn't a filming session, nor a rehearsal, but an opportunity to figure out camera angles.

What they did admit, though, was that the gun's chamber was indeed inspected and spun by their client -- and they say she put in 6 rounds (thinking they were all dummies) ... and did not realize a live round had been placed in the mix. After that, she pawned it off to assistant director David Halls ... who then went into the church with Alec Baldwin and the rest of the crew.

This is way more info than what she initially offered last week -- when she delivered relatively brief remarks that expressed condolences for Hutchins' family ... but insisted she did not know how live rounds of ammo made their way onto the set.

Gutierrez-Reed also insisted she and the head prop master gained control of all the guns on set each day, while saying she never saw anyone use the guns or put live rounds in them either. She says she never would've allowed that, as safety is her top priority on the job.

What's interesting about that claim is live rounds and dummy rounds do look the same from the front. In fact, the purpose of a dummy round is to be shown on camera when a scene calls for showing someone holding a bullet or to show a bullet in the chamber of a gun.

Gutierrez-Reed has also pointed out she was tapped for 2 positions on "Rust" -- which she says made it difficult to focus on her armorer duties ... something her attorneys say she fought back against, but was overruled by production.

Her attorneys made no bones about where the blame lies -- arguing it is NOT with Hannah. They say, "The whole production set became unsafe due to various factors, including lack of safety meetings. This was not the fault of Hannah."

Of course, there are a lot of eyeballs in her direction -- especially seeing how many believe she should've been the one to personally hand Alec the gun, and to also properly check it.

There's also the fact that she'd recently appeared to express some doubt about her abilities when it comes to the gig itself ... acknowledging she was pretty green to being a head armorer.