Apache redirectmatch is wrongly be applied to other vhosts
From the Name-based Virtual Host Support section of the Apache httpd manual:
The default name-based vhost for an IP and port combination
If no matching ServerName or ServerAlias is found in the set of virtual hosts containing the most specific matching IP address and port combination, then the first listed virtual host that matches that will be used.
Ie, it's generally a good idea to have a neutral first entry that is intended for the scenario that you get unexpected requests at some point.