Open a command prompt , then type
tracert 226.219.95.18 (the public IP for www.lilleyslanding.com and www.ozarkanglers.com)
This will possible show where the bottleneck is (an internal or external address where it either gets stuck or has a very long response time)
Many firewalls out there have their own content filtering without having to even touch the server on the network. It can be drilled down very tightly. It could also be a DNS problem.
He/She can also put the aforementioned IP address in the address bar of their browser and see if it goes to the BIMS website, if it does, then that means a likely DNS issue, which could be taking place directly on his computer or the DNS server it is working from (DNS Domain Name Resolution, that tells the computer which IP address to go to when you enter a name such as www.website.com)
Another quick thing to try would be to clear your internet history. I have people all the time who cannot access a specific site (due to all kinds of errors) but then it works after clearing history (one bad connection attempt that gets cached and needs to be cleaned out).
This also depends, can he access www.ozarkanglers.com and just gets blocked when trying to access www.ozarkanglers.com/forums?
I hope this helps...but if not I would be glad to answer any further questions