“So obvious perjury by a DA is ok with this judge...at least in this case for some reason.”
The judge isn’t a prosecutor. He can refer it but can’t prosecute it himself.
I will agree he can not formerly charge them with the crime of perjury like a prosecutor can. However not sure why he could not throw them off the case for unethical conduct in his court room...and obvious perjury seems pretty unethical.