He might not have been actively a physical danger, but he did make it physical. He was told no and still tried to push through. He then gets angry (indicated by him telling them not to touch him despite them simply standing firm). He then reasserts his intent to go past them. He gave every indication of escalating the situation. That’s a definitive threat. I don’t think they should have to play his stupid games and just push him back until he becomes more and more threatening.

The sovvy physically pushed his way into P. Barnes. P. Barnes is law enforcement assigned to that courtroom. Laying hands (or shoulders or knees) on a LEO is a crime in the US. Whether the taser was necessary is a separate issue.