Events, paypal and confirmations

I have a question regarding how Events+ works with Paypal, specifically around confirmations.

We've recently started running this plugin on the site and have a paid-for event working with Paypal. Already 5 people are listed in the backend event details dashboard page as 'attending' but only 1 has actually paid so far using Paypal.

So my question - when a user clicks the 'Attending' button and is taken through to the page with the Paypal button on, are they then marked as attending BEFORE completing Paypal, or does Events+ wait until they have COMPLETED the transaction?

Thanks!

James.