Need help trying to figure out a problem.

I did not mix this doough so im going on the word of my fellow baker that he put in all proper amounts of ingreedients.

The dough, when shaping was unusually slack/soft so to speak, but was not overly dry or wet.

The dough overproofed in the proofbox(was overproofed when i pulled it out, normally takes about 10-15min longer to overproof.)

The baguettes, which were put in the proofbox 10-15 mans AFTER the other dough, but pulled out at the same time, also overproofed?

What could cause this to happen!!

only thing i can think of is overmixing maybe...but ive never personally seen taht b4..so don't know!