Will a partners traffic be in our firewall logs?

So we have a a vpn setup to one of our business partners. The connection is active and they can route traffic to our site, let's call this site 1. They want to send traffic to another site so we setup a rule to forward vpn traffic to our other vpn, let's call this site 2. They have an extremely locked down network and only allow for certain traffic inbound and outbound on a specific port to an ip while we open our whole subnet to them.

They can't route anything to site 2 through this tunnel, however we can send from site 2 to them. I've looked through the logs and there is nothing destined for site 2 coming into site 1's logs.. they are adamant that their ruling is setup correctly so I'm not sure where to go from here.

If I can't see any traffic in our logs on site 1's firewall would this be an issue on their side?

Simple stuff here but I've been going crazy trying to fix. They also don't allow for icmp traffic.

Thanks