Based on what I saw, I think he's probably guilty but without intent. I see him lifting his feet in and around the tall grass, most likely out of a fear that he's going to step on his own ball.
It seems counterintuitive to me that he would stomp around with the express intent of improving his lie, because he's just as likely to make it worse under those conditions.
That said, his actions did improve his lie, and thus are cause for penalty.
As they said on TV, hopefully an hour or two of bashing balls around the range will remind him that he's merely three shots off the lead in the Open instead of one and give him cause to focus up. Because if we're in 2020 US Open Bryson mode through the weekend, it might just be whether he wins by four or six. That tee shot on the dogleg, other than braining someone in the last row of the bleachers, is one of those shots no one else on the property has.
As for Bryson the guy, he seems like something of a cross between Gronk and Mike Leach. If I could have 15 minutes on golf topics only, I think I'd find at least that facet of him fairly interesting.