B737 flight crew reported a Flight Attendant concern that they departed with snow on their wings although aircraft was deiced and departed within the calculated hold over time.

Narrative

Light snow prior to push; Deice Type-I 50/50. Anti-ice Lyondell Arctic Shield Type-IV 100%. Approximately 10 minutes prior to departure; snow intensity increased; estimated to be moderate. Holdover time 45 minutes to 1 hour 15 minutes. Departed 37 minutes after beginning of final application. All wing contamination was observed to shear prior to rotation during normal takeoff. After reaching cruises altitude; Captain went to lavatory and happened to overhear Flight Attendant Supervisor; who was on board as #4 Flight Attendant; mention her concerns relative to another airlines crash study. Captain felt it was prudent to file an ASAP for protection against any possible confusion or after the fact speculation; even though neither of us could determine any fault in our application of SOP. Supplemental information from ACN 819421: In cruse one of the Flight Attendants commented that she: 1) Thought we were returning to the gate to deice; 2) Had concerns that we departed with snow on the wings; 3) Had just come from Recurrent where they showed aircraft crashes from aircraft holding out for takeoff in snowstorms too long and attempting the takeoff. I feel that we complied with our Company procedures exactly as we have been trained and exactly as it is outlined in our manual. I do not believe we departed with ice/snow on the wings and further; the Type IV worked as expected; shearing during the takeoff roll. End of statement. I feel I should have been clearer with the Flight Attendants as to my intentions regarding when we would return to the gate should we be unable to depart. I also feel (and I communicated this to the Flight Attendant) that if she was concerned; she should have said so immediately and brought this to my attention. In discussion with all the Flight Attendants; I told them to always bring their concerns to the attention of the cockpit Crew as their input is valid and essential.