// Execute returns false, no exception thrown
$so = $rh->pdo->prepare("SELECT * FROM config");
if($so->execute(['Test']) === FALSE) echo '1. False returned <br />';

// Execute does not return false, no exception thrown
$so = $rh->pdo->prepare("SELECT * FROM config");
if($so->bindValue(1, 'Test') === FALSE) echo '2. Binding failed <br />';
if($so->execute() === FALSE) echo '2. False not returned <br />';

// Execute returns false, no exception thrown
$so = $rh->pdo->prepare("SELECT * FROM config WHERE webmaster_name = ?");
if($so->execute(['Test', 'Wee']) === FALSE) echo '3. False returned <br />';

// Execute does not return false, no exception thrown
$so = $rh->pdo->prepare("SELECT * FROM config WHERE webmaster_name = ?");
$so->bindValue(1, 'Test');
if($so->bindValue(2, 'Wee') === FALSE) echo '4. Binding failed <br />';
if($so->execute() === FALSE) echo '4. False not returned <br />';

Outputs:
1. False returned
2. Binding failed
3. False returned
4. Binding failed

$user_info = $rh->pdo->query("SELECT * FROM users WHERE user_id = 1")->fetch();

// vs

$so = $rh->pdo->query("SELECT * FROM users WHERE user_id = 1");
if($so === FALSE) // Throw an exception
$user_info = $so->fetch();