If the a Tor entry guard is running on the same server as the VPN Server (variable VPN_SERVERS), if the VPN breaks down, Tor may connect directly to the VPN if it happened to choose that as entry guard. This is a bug if the user wants to hide Tor.
The risk increases, if the VPN supports remote port forwarding, because that allows anyone to host a Tor entry guard and have it show up with the VPN's external IP.
It can be fixed by only allowing user tunnel to establish connections once VPN_FIREWALL has been set to 1. (As opposed to currently to allow connections to all IP defined by variable VPN_SERVERS.