Maybe I'm missing something here but... the only reason I can see to pour the solvent in a baking dish and evap half way would be if you used too much solvent to begin with. If the proper volume of solvent is being used there's really no reason to evap first, although it doesnt hurt. The point is that the whole evap'ing and then reheating and then freezing is an unnecessary step. If you were evap'ing in the baking dish, then why not just cover the baking dish with plastic wrap and do the freeze preicipitation in that? The crystals would be much easier to retrieve.   From the looks of the pictures, this guy had a pretty small amount of solvent to begin with and the crystals seemed to be precipitating just fine. The solvent looked cloudy as well so it was still precipitating. I think he may have just done some unnecessary work.    I would also add that a recrystallization after your precipitation would have solved your yellow/brown blob problem too.