FTA:

The suspect managed to evade authorities even though a photo showed he'd been wearing hand and ankle cuffs.
"I saw he escaped from the check-in counter at Sea-Tac," said Johnny Satterlee, Bates' friend who lives in Seattle. "It's genuinely impressive that he was able to make it all the way to the train station."
Authorities have not disclosed how exactly Stevenson evaded multiple contracted agents while restrained. The incident has raised questions about the protocols used in prisoner transport and airport security.

This case exposes one of the problems with privatizing security functions to contractors.