I've tried this out on our site & on a fresh install on Magento 1.9 with the RWD theme and no other extensions installed and the swatches don't load, I just see the ajax loader.
There are no errors in the chrome console but I do get this error in my NGINX log:
/var/log/nginx/error.log
2015/10/13 12:39:33 [error] 1340#0: *2931 FastCGI sent in stderr: "PHP message: PHP Fatal error: Cannot use string offset as an array in /var/www/magento1-9/app/code/core/Mage/ConfigurableSwatches/Helper/Mediafallback.php on line 360
PHP message: PHP Stack trace:
PHP message: PHP 1. {main}() /var/www/magento1-9/index.php:0
PHP message: PHP 2. Mage::run() /var/www/magento1-9/index.php:87
PHP message: PHP 3. Mage_Core_Model_App->run() /var/www/magento1-9/app/Mage.php:684
PHP message: PHP 4. Mage_Core_Controller_Varien_Front->dispatch() /var/www/magento1-9/app/code/core/Mage/Core/Model/App.php:354
PHP message: PHP 5. Mage_Core_Controller_Varien_Router_Standard->match() /var/www/magento1-9/app/code/core/Mage/Core/Controller/Varien/Front.php:172
PHP message: PHP 6. Mage_Core_Controller_Varien_Action->dispatch() /var/www/magento1-9/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php:250
PHP message: PHP 7. Wigman_AjaxSwatches_AjaxController->getlistdataAction() /var/www/magento1-9/app/code/core/Mage/Core/Controller/Varien/Action.php:418
PHP message: PHP 8. Mage_Core_Block_Abstract->toHtml() /var/www/magento1-9/app/code/community/Wigman/AjaxSwatches/controllers/AjaxController.php:74
PHP message: PHP 9. Wigman_AjaxSwatches_Block_Swatchlist->_toHtml() /var/www/magento1-9/app/code/core/Mage/Core/Block/Abstract.php:919
PHP message: PHP 10. Mage_ConfigurableSwatches_Helper_Mediafallback->attachGallerySetToCollection() /var/www/magento1-9/app/code/community/Wigman/AjaxSwatches/Block/Swatchlist.php:37" while reading response header from upstream, client: 127.0.0.1, server: dev.magento1-9.local, request: "POST /ajaxswatches/ajax/getlistdata HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "dev.magento1-9.local", referrer: "http://dev.magento1-9.local/women/tops-blouses.html"