I installed this and it is reporting and update to Admin Tools Pro: 2.2.1 version found. The problem is I have version 2.2.5 installed and it has been at that version for a month or so. I would say that is a bug?
Could you please go to Extension manager -> update. Click on purge cache and after taht on find update. Does it show admin tool 2.2.1 there?
I don't think it is a bug in the plugin - I think that this is what the joomla update function is saying... And all we do is -> call the joomla update function once a day and send you a mail.