Well, maybe a silly question, but is THIS situation a win or not? Game Rules say: "Timer starts(...) and ends when you hear the whistle after beating green Yoshi in Wedding Nails."
I recall asking ElectronicLogic this very question almost two years ago and he just laughed at me. Since the whistle occurs, by the wording of the game rules it would be a complete run.
If not, they need to change the language to fit their wishes.
To add my 2 cents I would consider it valid. If this run was being timed by a mod, the timer would stop at the whistle. what happens after the fact should be irrelevant.
By the letter of the law..... yes. By the spirit of the rule.... no. If someone submitted that and said "I heard the whistle!" I would probably approve it and then change the rule lol.