Some people carry what they are comfortable with or the situation warrents...
Some may only need a 7rnd subcompact... other times they get a full sized 15-20 rnd, with possibly extra mags.
If they get concerned, it may be a mp5k in a sling bag...
But in this case, pretti clearly carried a gun and was actively involved in protesting, showing intent to use it against ice officers... because he wasn’t going to be using it on fellow agitators, was he?
In many cases, that very much includes extra magazines. There's just nothing abnormal about that, as armed Citizen knows. Trying to make a big deal about it is ignorant.
I suspect that the people who make a big deal about it have zero personal experience with being an armed Citizen.