Hey guys, many of the 485 denials never make it on the boards.
There are generally two types of denials; one that can bar you from applying again (inadmissability) and the other is due to not doing fingerprints, responding to RFE notice, not getting employment verification letter, etc.
The inadmissability is the biggest issue because you wouldn't be able to file another 485 whereas the other categories you would be able to.
I have seen cases where: USCIS revoked approved 140 causing 485 denial, employer revoking 140 causing 485 denial (subsequently people got approved after using ac21). Person using ac21 and was asked to get a letter from 140 employer that they had intent to hire upon 140 approval but they couldn't get that letter. Persons brother was employer who sponsored person but because he was an asylee he couldn't give affidavit of support and the 485 got denied.
The inadmissability was mainly due to not maintaining valid h-1b status or violating it by not amending h-1b or having labor condition applications for various job locations. One person had interview in Dallas office and his case got denied because officer said he lied. Essentially, in the interview officer asked how much his salary was. He responded by giving his annual wage. Officer asked for w2's and he submitted them later. Due to bench time or leave of absence, the w2's didn't match up to what he had told officer earlier. In the denial notice, they accused him of lying under oath. Don't know what happened to his case.
Therefore, cases can get denied, but many of them don't make it on the boards.