Yes, when you use a rigid body, then it is physics. But in this case it comes from the character motion controller, colliding with the geometry. It seems to be a script. I did not look into details. But what you see is exactly the same scene with the same rendering setup. The only difference is the colliding.

And as you can see, physics is merely visible in the profiler.

I also experienced the orange script peaks in exactly the moments, when I ran into walls, boxes or against pipes.