From your link (paragraph B):
This time, with only ten days before JCSO's planned press conference on the success of its April 20 raid, the previously innocuous vegetation was considered to be wet marijuana plant material. Burns asserts that he field tested the plant material found on April 10 using a Lynn Peavey KN reagent test kit, and that it was positive for marijuana. However, there is no record of that test because, although Burns thought it good practice to photograph the results of field tests and had done so in other situations in the past, he did not take pictures of the plant material or the KN reagent test results. The deputies needed one more positive trash pull before they could seek a warrant. So, on April 17—with only three days before the pre-planned raid—Burns and Blake conducted one final trash pull from which they found the same green vegetation. They claim that vegetation field tested positive for marijuana, but once again, the officers did not photograph this crucial evidence.
So, a judge was told by two police officers that they had found evidence of marijuana in the Harte's trash, and a warrant was issued on the basis of that.
The issue is not the judge being reckless, the issue is that public officers misguided him in telling that they had "evidence" of marijuana cultivation.
And from the PS, the issue is that of presumption of innocence for the cops1. You should have to prove that they lied about the results of the tests2.
The text explains that the plant material was tested again and it gives a more complicated view of the issue:
The Hartes' retained expert, Michael Bussell, tested the exact same samples—using the exact same type of field test the deputies used—and yet obtained very different results: contrary to the deputies' alleged results, Bussell stated that the tea leaves tested negative for the presence of THC. A jury could reasonably infer from those negative results that Deputy Burns lied about obtaining positive results.
The district court disregarded this hard evidence for three reasons. First, the district court noted that the tea leaves were more than three years old when Bussell tested them. The district court reasoned that this fact undermines Bussell's testing[...]
Next, the district court noted that Bussell obtained a false-positive result when he tested a batch of freshly brewed tea leaves. In the district court's view, this positive result would preclude a reasonable jury from concluding that Deputy Burns lied about obtaining a positive result in 2012. [...]
Finally, the district court points to the test results obtained by JCSO's Crime Laboratory (the Crime Lab). Four months after the April 20 raids, the Crime Lab retested the original tea leaves, using the same field test that the deputies used, and obtained a positive result [...].
It is fair to note that the author of the text objects against the tests exculping the police officers for several reasons, but at the same time it shows that the issue was researched and -even if you believe that the end result was not satisfactory3- it was not just ignored altogether and the officers were indeed tried.
From the text:
I'm mindful of our precedent indicating that “to survive qualified immunity, a [Franks] plaintiff must make a substantial showing of deliberate falsehood.
2Again from the text:
The second policy at issue is Sheriff Denning's decision to authorize the use of inconclusive field tests with a high false positive rate, [...]
3I have to agree that the whole issue seems to have a rather bad smell.