California: Petitioners claim about "shockingly large" rejection rates

The lead petitioners in the recall of Los Angeles County District Attorney George Gascon are complaining about the procedures for signature verification. Petitioners claim that the 22% rejection rate is "shockingly large" which they oddly compare to a 2% rejection for vote by mail ballots, which are of course different. The problem is that (based on the SF recall efforts) most of the signatures are rejected because the voters are not registered or give a wrong address. The 22% signature failure rate is not that unusual based on past recall efforts.