Oh yes, I did enjoy reading that article. It was refreshing in today's world of 24-hour bite-sized news. All that trouble from such a little piece of radioactive cobalt. Imagine if some mad man decides to attach something like that to a cab in NYC. Just as stated in the article, it would cause a huge panic.
Radioactive stuff gets flagged all the time in major ports. As the article mentioned, kitty litter, and other natural things can set off the detectors.
As a general rule, a incident you read about in Wired is probably not the first or last of its kind. It seems pretty plausible that old medical stuff gets thrown in with scrap metal all the time.
I wonder if "new money" places like the petrodollar kingdoms and emirates might have the money to purchase and operate advanced medical machines but not necessarily the regulatory maturity to track the whole lifecycle through decommission and safe disposal.