Last time we made a change with our CDN provider some members had this problem. We recently parallelized the CDN (about 6 hours after the new site deployed) so this could be causing the issue.
I can think of nothing on the site side that would be causing this; tbh this is really just a modified version of the old ggFTW theme. If it keeps happening after a day or two then we need to look at it.
In the interim, could you please get his browser, browser version, operating system, and line speed info? Please PM those to me. Thanks.