I had read pp here and three things:
First, I was induced with ds3 and no problems with milk supply at all and he was being induced 3 weeks early due to Gestational Diabetes and he was estamated at being close to 8lbs. Which oddly enough he was close.
Two, with ds3 dr though I might have had retained placenta. If you had retained placenta from my understanding you would have had really high fever and all that goes with having any kind of infection.
Thirdly, 3rd degree tear would have nothing to do with low milk supply. With dd I had a 4th degree tear and hemoragged(sp) and no impact on milk supply.
I don't think the induction it self, retained placenta or even the 3rd degree tear had anything to do with low milk supply. I would probably go with the fact they might have had gestational age off way too much.