While I think that’s absolutely true, it may not have been that obvious to the casual eye.
All three of them may have been able to look somewhat “normal” for a short period while they interacted with the police, even if they were far from normal under the surface.
Also, if the police had not dealt with MB much in the past, it may have been much less obvious to them how altered he was from his usual behavior.
Unlike someone like the health department witness or the hay guy, who had interacted with him for years, and thus were much more able to recognize the dramatic change in him.
And as someone said upthread, MB on a bad day in late July of 2019 might not have looked that different from a lot of the people the police saw all the time.