`wp_sentry_before_send`: `$event->getLevel()` result can be null

[astratagem]

I am trying to set up event filtering using wp_sentry_before_send but am encountering some rather confusing behavior where the error event has no level for comparing against a Sentry\Severity object. This behavior was what prompted me to open #240, but after diving deeper, I'm not so sure.

Following the example in the readme, I added the following near the top of plugins/hello.php:

$this->functionFailsForSure();

And here is my filter, which lives in mu-plugins/000-monitoring.php:

add_filter( 'wp_sentry_before_send', function ( \Sentry\Event $event, ?\Sentry\EventHint $hint = null ) {
    if (($hint === null) || ($hint->exception === null)) {
        return $event;
    }

    var_dump($hint->exception);
    var_dump($event->getLevel());

    $level = $event->getLevel();
    $isWarning = $level === \Sentry\Severity::warning();
    $isPluginHelloDolly = strpos($hint->exception->getFile(), 'plugins/hello.php') !== false;

    if ( $isWarning && $isPluginHelloDolly ) {
        return null;
    }

    return $event;
}, 10, 2 );

On the site homepage we have the output from var_dump().

Here is $hint->exception:

/var/www/html/wp-content/mu-plugins/000-monitoring.php:44:
object(Error)[1008]
  protected 'message' => string 'Using $this when not in object context' (length=38)
  private string 'string' => string '' (length=0)
  protected 'code' => int 0
  protected string 'file' => string '/var/www/html/wp-content/plugins/hello.php' (length=42)
  protected int 'line' => int 20
  private array 'trace' => 
    array (size=5)
      0 => 
        array (size=3)
          'file' => string '/var/www/html/wp-settings.php' (length=29)
          'line' => int 560
          'function' => string 'include_once' (length=12)
      1 => 
        array (size=4)
          'file' => string '/var/www/html/wp-config.php' (length=27)
          'line' => int 227
          'args' => 
            array (size=1)
              ...
          'function' => string 'require_once' (length=12)
      2 => 
        array (size=4)
          'file' => string '/var/www/html/wp-load.php' (length=25)
          'line' => int 50
          'args' => 
            array (size=1)
              ...
          'function' => string 'require_once' (length=12)
      3 => 
        array (size=4)
          'file' => string '/var/www/html/wp-blog-header.php' (length=32)
          'line' => int 13
          'args' => 
            array (size=1)
              ...
          'function' => string 'require_once' (length=12)
      4 => 
        array (size=4)
          'file' => string '/var/www/html/index.php' (length=23)
          'line' => int 17
          'args' => 
            array (size=1)
              ...
          'function' => string 'require' (length=7)
  private ?Throwable 'previous' => null

And then $event->getLevel():

/var/www/html/wp-content/mu-plugins/000-monitoring.php:45:null

If $event->getLevel() can sometimes result in a null value even when $hint?->exception !== null, how can I reliably filter events by log level?