I may be wrong, but it seems the fault tolerance can be adjusted by the provider. More mainstream sites that use them (like Patreon) seem to commonly let you through after one screen where more spammy sites (like less-reputed download providers) will force you through several of them. Whether it's due to honest false negatives or the system forcing you through it twice by wrongly saying you're wrong, I can't say. All I know is that they demand a lot more from you.
Biting the hand that feeds IT
