udp packets and firewalls

[Wayne Vigeant]

I'm currently working with a customer who has a single Internet
access point. The customer's firewall allows dns queries from the
Internet to pass through to an internal nameserver.
The customer wants to add a second Internet access point and allow
dns queries to pass through both of the Internet access points. 

The customer's firewall is a packet filter and allows UDP packets
to port 53 to pass in either direction (inbound or outbound). Is
it safe to say that since only UDP packets are being allowed that
a query which comes in to the internal network through a firewall 
in Singapore can be replied to by a response which passes outward 
through a firewall in Tokyo?

Does the nameserver making the query care if the reply follows the
same path as the query? It would appear not to matter but I just want 
to be sure bind doesn't care.

Thanks.