returning null compared to throwing an exception

exception.php

<?php

$person = $peopleRepo->getLatest();

if (null === $person) {
  $log->warn('No person found');
}
$person->inviteToParty();

// becomes

try {
  $people->getLatest()->inviteToParty();
} catch (NoPersoFound $e) {
  $logger->warn('No person found');
}