The quick answer, is that with knits, there is no difference. The longer answer is more nuanced. All three are made by hand. There are a few differences that set Haute Couture apart:
The maker is a dedicated craft specialist, using materials of the highest quality (alternately using exclusive, luxury fibres). And of course, the finishing. If we take the time to get the finishing just right, then there is no difference between homemade and Haute Couture.