There are logical reasons...and I'm sure those reasons have been communicated to BIEL. FDA doesn't just reject without cause, and then not tell you what you would need for approval. They won't tell you specifically...and that is the black hole.
If BIEL followed the recommendations given over these past years (jeez has it been that long?) by FDA (high level), translated them into more detailed requirements (using their consultants), then were able to submit documentation to FDA that shows that they meet these requirements, we're good.
But it's how BIEL INTERPRETED the recommendations from FDA. FDA will never tell you exactly what is required for approval/clearance, so hopefully (and this is what we are all betting on) BIEL got it right this time, that is, the documentation that supports the detailed recommendations put for by the consultant, which are in alighment with FDA's higher level recommendations.
In the end it's a crap shoot, really, for any company. This is part of the problem. Because the requirements are not black and white, they are interpreted by each company, as well as each inspector.
Depends on the day, depends on the mood...not a real 'scientific' approach.