Routers / Port Forwarding / NAT / SBS / Static IP - a question about all of that!

I was working with another guy at our church who set up the network there.  I'd like to get your opinion on what he told me.

Background: It's a network with a single nic sbs box, NOT being used for email.  It does the DHCP for the network of about 5 PCs.  The router is a consumer grade blue linksys router (with LAN IP of 192.168.1.1).  They have STATIC DSL.

We got into a discussion on changing things on the network.  He said that 1 person remotely accesses the info on the server (it has the IP of 192.168.1.110) via Telnet!?  I clarified - not RWW, not logmein or gotomypc... telnet he said.

Looking at the router interface briefly - I saw the static IP hard coded on the router.  DHCP on the LAN side was turned off.  There were NO port forwardings set up on that page and the DMZ page said 'disabled'.

So with a static public IP, is there any way they are remotely getting into the server via telnet with the screens set up the way I described?  Again, single nic server and that has an IP of 192.168.1.110 and another machine on the network has 192.168.1.103.

I will push it with 'when was the last time they connected' and how do they connect, etc..... but I want to make sure I am right - from what I saw, no one can get in remotely via telnet?

it's something like a BEFSR41 or similar type of router.