CallTracker::onAfterDelete

static function onAfterDelete(
	int $id,
	array $activityFields,
	array $params = null
)
{
	$completed = isset($activityFields['COMPLETED']) && $activityFields['COMPLETED'] === 'Y';
	$deadline = isset($activityFields['DEADLINE']) ? new \Bitrix\Main\Type\DateTime($activityFields['DEADLINE']) : null;
	$userId = isset($activityFields['RESPONSIBLE_ID']) ? (int)$activityFields['RESPONSIBLE_ID'] : 0;

	if (self::needUpdateCounter($completed, $deadline) && $userId > 0)
	{
		$counter = \Bitrix\Crm\Counter\EntityCounterFactory::createCallTrackerCounter($userId);
		$counter->decrease();
	}
}