"While that is true, it is also true that the checks issued through
purchase orders are issued by the appropriate financial departments of
the company issuing the purchase order and generally sent via mail to
the financial receiving department of the company with whom the
purchase order was placed. In my experience, it would be very unusual
for a person to deliver a check in person. "

The check was issued by the company.

Sure, for the average "widgets" a company will send a check. However,
when cash or near cash items are involved it is the always the case
that a real live human being will deliver payment in person when the
transaction involves purchasing items such as this. (Gift cards are
like cash) That person will be either a trusted company employee or a
bonded messenger. In my 20+ years as a professional financial manager
this has ALWAYS been the case. Though I've only seen messengers
trusted with securities. Cash or near cash items are always handled by
employees. If I were GAF's CFO I would have been damn glad that it was
another member of senior management was the one running around with 10k
of cash rather than just anyone.