Yup dp I've put frames w/ bees in another hive before too, mainly out of laziness. Maybe the queen got caught up up in the resulting squabble & got injured, but if it's a weak hive anyway, maybe (another thing I was taught) cut your losses in the fall, squash the qcells & combine, that way you'll have a stronger hive for a spring split.
Watch it closely. As already said, a combine may be in your/their near future for best chance of survival. I've got one that may get the same treatment, but I've got less time right now.
Nothing wrong (or lazy
about providing more bees to a weak colony from a strong one. Its a win-win in most cases in that it inhibits swarming in the strong and strengthens the weak. IMHO; It is important to provide several shook frames of 'nurse' bees along with the frames of brood though, they won't leave the brood.
I usually try to 'shake' twice as many frames of nurse bees as the frames of brood I take (works for making NUCs too). This seems to provide a healthy number of bees to do the inside work needed to get going for buildup.....in my experience anyway. Good Luck.