The actions taken count is simply the number of times the initial 'Submit' button is clicked. That click, however, doesn't always guarantee a successful message will be sent.
For example, if the system needs to come back for further information from the supporter, and the supporter bails on the process, then their click will still be counted, but their message(s) will never be sent. There are other, less common scenarios, such as a browser/computer crash after clicking 'Submit', but that's not as likely.
Unfortunately, there isn't a detailed log of what occurs after that 'Submit' button is clicked, though we do track how many messages were actually, successfully sent out.