A former 'Bachelorette' producer is calling BS on the idea that ABC was blindsided by Taylor Frankie Paul’s physical violence allegations involving her ex, Dakota Mortensen ... telling us there’s just no way that slipped through the cracks.

We spoke with Michael Carroll on "TMZ Live" Wednesday ... and he says back in his day, casting was unbelievably strict -- with deep background, medical, and psychological checks on every contestant ... adding that anyone with charges like that against her would’ve been an automatic no.

Catch the full clip ... 'cause Michael doubles down, telling us current producers were fully aware of who the 'Secret Lives of Mormon Wives' star was. In his view, this wasn’t a surprise -- it was a setup ... calling it a publicity grab.

And LBR, with "The Bachelorette" now 24 years in and losing steam against hotter dating shows, Michael says the franchise has been feeling a little stale. So, a shake-up like this? He admits it’s the kind of drama that might actually pull viewers back in -- even himself.

As for Taylor, Michael tells us producers will likely try to spin the narrative ... making it seem like she needed the show to turn her life around.

As we first reported ... Taylor and Dakota Mortensen have been ordered to undergo psychological evaluations following allegations of physical violence -- with concerns from the 'Mormon Wives' cast already halting production on Season 5.