Would likely filter out many (perhaps most?) contams as the fermenter fills with outside air.
My (admittedly overly emphasized) concern with cold crashing is the oxygen that fills the fermenter.
I use a Speidel right now with a second spigot on top vice an airlock - so, what I started doing is closing the top spigot and letting it cold crash ~ half way to 32; when the Speidel lid becomes inverted from the vacuum (but before the sides crush inwards) I pressurize the Speidel with CO2 from the top. Then as it continues to cold crash, the pressure is roughly equallized, and all that's in the fermenter is CO2, and no contams (or, very minimal anyway).
Now that I plan to use 6.5 gallon corny kegs for fermenting, this will become even easier - no contams, no issue with oxygen intake (can hold 60psi, so I can pressurize before cold crash).