Captain Airclues:
There is a scary CRM video shown to us in Europe. It covers de-icing as well. It was on an F28? and sounds just like your scenario as it was in Canada. The crew were behind schedule. You guessed it, it was snowing, the APU was U/S,, the ground starter was unreliable, there was no de-icing with the engines running (SOP's). A pax, pilot I think, asked the C/A to tell the captain there was a lot of snow on the wings. She went away, returned and said it would blow off on takeoff.
Guess again! Crash!!
It is the captain's legal responsibility to ensure the surfaces are clean. He can delegate this or do it himself. Either way he makes the call. It has been well known in Scandanavia for years that a tactile test is the only 100% sure way, in nasty icing conditions, especially where ice has been present.
There was case recently where Type 1 was ordered and 100% water was used. A/C called back from taxi by the de-ice company. Could have been VERY serious. And not to mention the numerolus incidents/accidents where assymetric ice caused by cold soaked fuel has led to some 'recovery from unusual attitude' demonstrations.
Surely the pax would like to see a sound professional flight preparation. There are already too many dilutions of that on clear sunny days. Let's not allow more to happen in critical situations. Remember the lack of respect/knowledge for icing that might have led to the winter dip in the Potomac.