Bone Graft Failure

I recently had a bone graft procedure (2 upper posterior premolars).
Right after the surgery I have been told that "everything" looked perfect. However, after +24 hours I started to experience unbereable pain on the surgery site.

Few days after the surgery the Doctor saw me again, and they "suppossed" I may be having an alveolitis, which they did not confirm.

On the 7th day postsurgery, I was told that the graft and the membrane were still in place and that I was suffering from a dry socket situation, caused by the lost of the blood clot.
On day 8th after surgery, on another consultation it was determined that the membrane and graft were definitely gone.

I wonder if
a) this could have just happened overnight (taking into account that on day 7th "apparently" everything was OK; and
b) if a preoperative sinusitis -which started a week before surgery and lasted for about another week postsurgery- could have been the leading cause to bone graft failure.
c) since after a previous bone graft procedure I went through the same unbearable pain starting +24 hr postsurgery (the graft was however successfull), I wonder if there a patient could  be prone to suffer a "chronic dry socket" situation and if so, if there are any methods to prevent it.

Many thanks,

Jean Jacques