traceroute continuing after destination?

Solution 1:

4.4.4.4 is not returning the correct response to show the destination has been reached. Traceroute relies on this reply (ICMP Port Unreachable according to the link you provided - I remember it from working with traceroute but can't remember the precise signal name).

Traceroute itself doesn't just check for a response that comes from the destination, just the type of response received to check if it has reached the destination.

So I would guess that ICMP on 4.4.4.4 is a problem, either through a Firewall blocking issue or some sort of port-forwarding configuration.