workflow_execute_transition, always adds author role in permission check?

In order to add quick links on nodes to change the state without having to go into edit, I'm calling workflow_execute_transition via links added to the node from a custom module (i.e. menu item /state/nid/sid calls a custom function which in turn calls workflow_execute_transition). It works great, except that all users seem to be given the author permission by the function (so users that are not actually the author of a node, can change that node's state).

The line producing this behavior is around 466:
if (!workflow_transition_allowed($tid, array_merge(array_keys($user->roles), array('author')))) {

I could be understanding this wrong, but it seems that line always adds the role 'author' to the user. Is there a reason for this? I copied/modified code from earlier on in the module to check if the user actually is the author:

$roles = array();
if (($user->uid == $node->uid && $node->uid > 0) || (arg(0) == 'node' && arg(1) == 'add')) { 
  $roles[] = 'author';
  }

and replaced the previously mentioned line with:
if (!workflow_transition_allowed($tid, array_merge(array_keys($user->roles), $roles))) {

This seems to work great, I'm just wondering if there was a reason for always assigning the author role to user permissions in this function.

Thanks!
Brian