In trying to copy over a theme and partially start over I ran into an issue where WordPress wouldn’t show anything but one word, error. Well, that’s helpful. Searching the wordpress forums I found that the problem is actually a security measure from Better WP Security. Since my newly copied/created theme had so many missing files (404 errors) it blocked me out. Deactivating that plugin (programmatically) caused the issue to go away.
Source: http://wordpress.org/support/topic/getting-one-word-error-when-logging-into-wp-loginphp