Submit handler: Prevent other handlers from running in certain circumstances only
By the time your submit handler is running you cannot change the other submit handlers that are running.

What you could do is make sure your form alter runs last (change the weight of your drupal module in your install file to a highier number to make it run later).
That way you can be a bit more sure that no one else is adding submit handlers after your form alter.

Then in your form alter do something like this:

// Add the original submit handlers to the form state for us to use later.
$form_state['original_submit_handlers'] = $form['#submit'];
// Replace the original submit handlers with out own.
$form['#submit'] = array('honeytrap_submit_handler');


Then in your submit handler:

if (honey_trap_fails) {
  // Do whatever, but don't call the original submit handlers.
}
else {
  // Do whatever, and then:
  // Call the original submit handler because it was a successful submission.
  // Replacing yours as it has already been called.
  $form['#submit'] = $form_state['original_submit_handlers'];
  form_execute_handlers('submit', $form, $form_state);
}


There is something important to take into account here:
If there are submit handlers on the button that was clicked then they will take precedence over submit functions attached to the form.
See form_execute_handlers() for a bit of further insight on how to handle button submit handlers.