Thanks to one of my users, he alerted me to an issue where Alexabot was being blocked out of his server. Even though Alexabot is not listed anywhere on the blocker it was being picked up and blocked out.
This was due to the existence of a bot called "exabot" the blocker was detecting the exabot part of Alexabot
This issue has now been been resolved with an exact matching regex on all the bots.
So all regex matching for User-agents has been changed from:
BrowserMatchNoCase "Exabot" bad_bot
to
BrowserMatchNoCase "^Exabot" bad_bot
Making the match exact and precise.
Fixed in all versions CentOS6, CentOS7 and the Base Repo version.