PHP - Moved: Trigger Event When Browser Is Closed

I have a listener which executes a HTTP request to a remote API before the User entity is persisted and uses the response to set one of the entity's properties.  It will also listen for update and remove and will make the appropriate HTTP request to the API but will not modify the entity.  All works as desired... Almost.  If when persisting the entity, I have some error, the remote API and my application become out of sync.  I wish to change my application to perform a second call to the API if an error occurs and reverse the previous call.  My thoughts on how to implement a

<?php

namespace App\EventListener;

use Doctrine\Persistence\Event\LifecycleEventArgs;
use App\Service\HelpDeskClient;
use App\Entity\AbstractUser;

final class UserListner
{
    private $helpDeskClient;

    public function __construct(HelpDeskClient $helpDeskClient)
    {
        $this->helpDeskClient = $helpDeskClient;
    }

    public function prePersist(AbstractUser $user, LifecycleEventArgs $event)
    {
        $this->helpDeskClient->addUser($user);   //$user will be updated with the HTTP response
    }

    public function preUpdate(AbstractUser $user, LifecycleEventArgs $event)
    {
        $this->helpDeskClient->updateUser($user);
    }

    public function preRemove (AbstractUser $user, LifecycleEventArgs $event)
    {
        $this->helpDeskClient->deleteUser($user);
    }
}

Okay, how do I actually do this?  Was thinking of modifying UserListner as follows:

//...
use Symfony\Component\HttpKernel\KernelEvents;

final class UserListner
{
    // ...
    
    public function prePersist(AbstractUser $user, LifecycleEventArgs $event)
    {
        $this->helpDeskClient->addUser($user);
        
        $event->getObjectManager()->getEventManager()->addEventListener(KernelEvents::EXCEPTION, function($something) use($user) {
            // Use $this->helpDeskClient to reverse the changes
        });
    }
    
    // Similar for update and remove
}

But when trying this approach, I get a PDOException, but my callback never gets excecated.  I've also tried replacing KernelEvents::EXCEPTION with '\PDOException' (note the quotes) with no success.

Any ideas what I should be doing differently?

Maybe some totally different approach?  I suppose I could make the request to the API after the DB query is complete for updating and deleting, but not for adding.