From the late 90s to early 2000s I worked for UUNET/Worldcom as an engineer in the network planning and design group. I worked in the international group but among other things we were responsible for the build out of AS701 into Canada, the exchange sites where AS701 connected to the various other international UUNET AS's and the PoP's where dedicated circuits for international customers who wished to connect directly to AS701 would be terminated. The point being that I am familiar with how AS701 was operated at that time.
UUNET's reputation at the time might not have been sterling due to the business decision to basically be a safe haven for spammers but from a technical standpoint the network was operated at a high standard. The basic BGP filtering referenced in the article was certainly in place at the time and if this had happened then heads would have rolled.