Wrong. WM policy is that the only people allowed to detain you is Loss Prevention and only then when the LP has witnessed you select the merchandise, retrieve it from the shelf, conceal the item (not applicable in this case) and then avoid the final point of purchase and then exit the store without offering to pay for the item. If the LP loses eye contact at anytime during his observation he/she is not to even talk to you let alone attempt to prevent you from leaving the store.
As to the door greater, WM policy strictly states that they are never to ask you for a receipt or try to prevent you from leaving the store unless the EAS (Electronic Article Surveillance) is activated. At that point the Door Greater can ask you for a receipt only to find out which register failed to deactivate the EAS device. However, if the customer refuses to offer the receipt the door greater must allow the customer to leave.
That might be written policy, but it ain’t how they train the Receipt Nazis.
Intentionally, I’d bet. So when sued they can maintain plausible deniability.