Then the judges are useless. If the FBI can come in and lie to them and the judges just accept that and don't say anything like: "that's a very serious charge against a newly elected president - are you sure of this and how?" then they are totally useless to protect Americans from their own government.
The FBI are not supposed to LIE. If a sworn LEO comes before you as a judge, and swears to the veracity of their probable cause material to get a warrant, you rule on what you have. If there are glaring inconsistencies, you say "No".
But at what point should we have to deal with sworn LEOs like 'hood rats insofar as the veracity of their sworn testimony?
That those same LEOs withheld exculpatory material makes them all the more at fault, because they went in with the intent to deceive in order to get the warrant, in violation of their oaths.
I would have to see what they presented the judge before I could fault the judge. If there were obvious and glaring problems with the evidence presented to establish probable cause, then the judge should be in trouble, too, but I would think that what was presented was slick enough to pass muster to get a warrant, especially in light of the low threshhold for probable cause for conducting searches on ordinary folks.