Don't accept anything ever : if buying that thing would have cost YOU, the physician some money (however little) : Don't accept it as a gift from the patient.
(UW is written by a group of doctors, who will mostly be correct , but in BS and some controversial topics, there will be issues..I would say stick to general principles there)
When they say token like cookies should be accepted, I would say a "thank you" card would be fine too..Homemade stuff, the kind one would include in a care package for a dear one living faraway e.g. cookies should be okay..because traditionally that is considered a pure form of affection for friends and family, and in the physician-patient relationship : a token of simple gratitude. Similarly, you treat someone successfully in the summer and he returns with some of Christmas cake...you accept it. But if he invites you out on a dinner in ANY restaurant...expensive or a cheap take-away, you REFUSE in the test scenario.
Basically, things that are very very basic forms of expressing gratitude : traditional forms, something that COULD not be considered as bribing a person/ treating him like royalty to seek favors l8r / super- expensive that even the doctor couldn't have afforded/ the kind if the doctor resold would earn him handsome returns / the kind of huge perks a company would award its executive on generating lots of revenue, e.g. sponsoring a holiday trip (which a really really rich patient could
) : such stuff SHOULD BE POLITELY REFUSED.
Accepting a gift and saying "he is receiving the same std of care" sounds more like justifying what you are doing..I think.