Forkish Saturday White Bread

I just purchased Forkish's book FWSY - and immediately made the Saturday White Bread - the first attempt the flavor was great, but I didn't read the instructions properly and baked seam side down, oops and I didn't score it either, double oops - no cracking, instead it made a giant air bubble which deflated. Tried again, this time seam side up, came out great. But I noticed both times that after proofing, when turned out onto to the counter from the form, the dough was a little slack and lost a bit of it's shape. I don't know if the dough was slightly overproofed (although the finger dent test seemed to be ok) or if this is the nature of the dough. The bread is delicious! Thanks for the help!