There appears to be an error on line 662 or wp-customer-admin-reviews.php

 

<label for="leave_text">Text to be displayed above review form: </label><input style="width:250px;" type="text" id="goto_leave_text" name="goto_leave_text" value="'.$this->options['goto_leave_text'].'" />

 

It is repeating the goto text which is that of the button above the form. Change this line to.

 

<label for="leave_text">Text to be displayed above review form: </label><input style="width:250px;" type="text" id="leave_text" name="leave_text" value="'.$this->options['leave_text'].'" />