core-site-install invocation does not check for settings.php in core-quick-drupal installation path

It looks like the code in drush_core_pre_site_install() method of site_install.drush.inc considers the root Drupal path relative to the current working directory of Drush, despite when calling core-quick-drupal, it shifts the base Drupal root into two sub-directories from your current path by default. I deduced this because there is a sites/ directory sitting in my ~/Documents/Code/ directory after drush qd is executed.

This results is the following error output from Drush with debug indicating that the core-site-install invocation during core-quick-drupal is failing when trying to copy sites/default/default.settings.php:

The directory /Users/jmlane/Documents/Code/quick-drupal-20111120043243 does not exist.
Would you like to create it? (y/n): y
Project drupal (7.9) downloaded to                                   [success]
/Users/jmlane/Documents/Code/quick-drupal-20111120043243/drupal.
Project drupal contains:                                             [success]
 - 3 profiles: testing, standard, minimal
 - 4 themes: stark, seven, garland, bartik
 - 47 modules: drupal_system_listing_incompatible_test,
drupal_system_listing_compatible_test, user, update, trigger,
translation, tracker, toolbar, taxonomy, system, syslog, statistics,
simpletest, shortcut, search, rdf, profile, poll, php, path, overlay,
openid, node, menu, locale, image, help, forum, filter, file,
field_ui, text, options, number, list, field_sql_storage, field,
dblog, dashboard, contextual, contact, comment, color, book, blog,
block, aggregator

You are about to create a sites/default/files directory and create a sites/default/settings.php file and CREATE  the '/Users/jmlane/Documents/Code/quick-drupal-20111120043243/quick-drupal-20111120043243.sqlite' database. Do you want to continue? (y/n): y
copy(sites/default/default.settings.php): failed to open stream: No  [warning]
such file or directory drush.inc:721
Failed to copy sites/default/default.settings.php to                 [error]
sites/default/settings.php
PHP Fatal error:  Call to undefined function user_load() in /usr/local/Cellar/php/5.3.8/lib/php/drush/commands/user/user.drush.inc on line 474
Drush command terminated abnormally due to an unrecoverable error.   [error]
Error: Call to undefined function user_load() in
/usr/local/Cellar/php/5.3.8/lib/php/drush/commands/user/user.drush.inc,
line 474

I am running Drush 5.x from pear.drush.org channel with PHP 5.3.8 on OS X 10.5.8, thus the funny paths in my stderr.