Waving the flag of another country whilst dressing in officer uniforms is absolutely not protected by free speech.

If Pakistanis tried this in India for example they would be imprisoned or shot.

Every single defence department on earth would view this is as a potential threat to their sovereignty and overall legitimacy as a government. That’s not to say they would react with brute force or react at all if they don’t view it as a ‘genuine’ threat. But they would absolutely view it as a potential for escalation.

Intelligence agencies would view it as a foreign civilian paramilitary/militia demonstration taking place on domestic soil.