Loropetalum losing its leaves after recent trim/ repot.

Hello,
My name is Todd, and recently I have gotten back into the hobby of growing bonsai, and decided I'd head down to the local Lowes and poke around the garden section to see if they had anything with promise. I found a beautiful Chinese fringe flower with just the right branch positioning and trunk shape for a very nice informal upright, and hurried home with it. I trimmed it back a good bit, and found a very lovely tree hidden inside. I trimmed maybe 1/3 of the foliage away. There were two small branches that were just a tiny higher than I'd like them, so I wired them down just a bit. Now I know there is rarely any instant gratification in bonsai, but this little fellow looked fairly close to perfect for an untrained nursery stock, and the next day I just couldn't help myself but to put it in a nice little pot I found in storage. That was about 2-3 weeks ago, and ever since then, every day Ive noticed 4-5 leaves turning a bright red color and falling off. Is anybody familiar with this species? Are they prone to lose their leaves easily? And if so, is this typically severe or just a natural reaction to any stress? I should also mention that I unfortunately do not have a yard or a deck, and live in a 6th floor apartment, so I do have to keep the tree on a large north facing window, but there should be absolutely more than enough light, and a little research before buying the plant showed that it is generally OK for growing inside. Any advice is welcome!

the pot is much shallower than the original nursery pot, but the volume of soil that it holds is actually not much less. maybe about 2/3 the size of the original nursery pot. Here is a picture, though it is hard to tell.

I don't have an answer for you. I quit trying to work with them after I killed too many.

I've never had any luck with them, either. They just don't want to be potted plants, and keeping one inside should make it twice as difficult. Add the root work you did, and I would have little hope. If you must grow inside, I suggest one of the small-leafed Ficus.

Your eyes may think there is a lot of light beside the window, but the plant will not. Our eyes adapt to light intensity. They merely demand as much as they can get.