It stalled on me this morning too but returned to normal around 5 AM. They’re probably doing server maintenance.
When you see a chain of timeouts like that in one section of the route, but success at the end of the route, it usually just means that the routers in that section are configured to ignore ICMP requests. Seems kind of anti-social to me, but it's not at all uncommon. I saw the same unresponsive section last night from my site, and it's still the same today, even with CT back on its feet.
Good point! I've also seen this when a site's primary DNS server becomes unavailable. (lol..."anti-social"...good one!).