Jet Direct used as router?

I asked my Network Guys to allow a printer to be shared by two users on 2 networks.
User number 1 is connected directly to the printer by usb cable. User 1 is on a different network.

Network 1 is a simple windows 2003 cluster server with windows 2000 or windows XP clients using windows networking and TCPIP over cat6 ethernet, a local provider has T1 fiber connections at the location.

Network 2 is a simple connection to a T1 router to a local provider also fiber.
The network uses Novell ver 491 SP4 and Active Directory, the servers are off site they are part of a much larger Metropolitan Area Network or MAN.

The network on this remote site is also Cat6 ethernet using dhcp for the clients and static IP for printers.
There is a CISCO Switch onsite which supplys connectivity.
User number 2 is connected through a MAN file and print cluster to an HP Internal jet direct card with a static IP address.

User number 2's network has no cross connectivity with the network of user 1 and we would prefer it stays that way.

My problem is one of understanding.

Network Guy number 1 says the printer will become a bridge between the 2 networks and will cause security issues.

Network Guy number 2 says there is no way this can happen.

Who is right? and maybe more importantly why? If there is a way the bridge could be created how can it be removed or blocked?

Thanks in Advance