The argument that there was no probable cause is very unlikely to hold up in practice. The law is very lenient to the issuance and execution of warrants.
Warrants are favored in the law and utilization of them will not
be thwarted by a hypertechnical reading of the supporting
affidavit and supporting testimony. For the same reason,
reviewing courts will accept evidence of a less "judicially
competent or persuasive character than would have justified an
officer in acting on his own without a warrant." Courts will
sustain the determination of probable cause so long as "there
was substantial basis for [the magistrate] to conclude that"
there was probable cause.
Shouldn't the person the warrant applies to be served and/or notified of the warrant and given a copy? I was under the impression that a warrant was a way to give police rights that they do not typically have according to civil rights. It's a civil contract that they will not exceed the rights they are given, so I'd assume he should be given a copy with an explanation of why his rights are being lessened temporarily.
If you're interested in some of the intricacies of 4th Ammendment jurisprudence, http://www.law.yale.edu/documents/pdf/1994Fourth.pdf is a phenomenal article.