They can have humans entering data manually but have safeguards in place to protect data - usually done by either hiring people in-house or having a contract with a firm that employs a regular set of people to do this work.
Sending the data to Mechanical Turk implies basically none of that safeguarding. Yeah, it's possible to do it, but from the sounds of it - especially given Expensify's appalling response - it's pretty apparent that they didn't.
"Um, you pretty clearly have some human wearing a costume and playing chess."
'No, no, I insist, it's 100% machine that happens to be good at this task!'
Now it's:
"Um, you pretty clearly must be using humans to interpret the receipts."
'No, no, I insist, it's all done by our proprietary algorithms!'
Are humans any better at it than computers? I wouldn't think that humans have a good enough heuristic that the extra 1000x processing speed isn't more of an advantage.
Quick, what's Barack Obama's race?
(Hint: your answer will depend on your culture and what you know of his ancestry and upbringing.)
You took one word out of his entire point and decided to make a statement about that.