Despite the dramatic online footage scene, the actor's not in trouble at all -- a Cochise County Sheriff's Office spokesperson tells TMZ Doug's Arizona home was used for a training mission by the county SWAT team ... and he gave them the full go-ahead to do so.

A spokesperson clarified when the training kicked off, nobody was home. But, Doug showed up during the final training scenario, asked to join as a role-player, and got the green light. It was all voluntary.

Historically, community members haven’t been part of SWAT training drills ... but Doug made a rare exception in this case.

We're told the SWAT team was honing their tactics, processes, and various other measures during the training.

TBC ... Doug was not arrested and wasn’t involved in any illegal activity. The sheriff’s department has been in touch with him, and told us he's planning to release a statement soon.

This clears everything up 'cause the scene did look super real -- it showed Doug appearing to be "apprehended" by multiple armed men entering his home, with one figure clearly identified as him by viewers. There was also another guy in the house who was involved in the role-play.