My first thought was that at the very least he should be comparing it to a tcp-traceroute (i.e. traceroute -T ...) rather than an ICMP one. Other routers before

My first thought was that at the very least he should be comparing it to a tcp-traceroute (i.e. traceroute -T ...) rather than an ICMP one. Other routers before them may make different routing decisions based upon the type of IP traffic, so assuming both take the same path is unsafe.