Currently, the index validation code only mentions that a corrupt index has too many or too few index entries. But the code has knowledge of which documents are missing index entries, which index entries are missing documents, and which index entries are incorrectly referencing the same document. It would be helpful to display this information when the validation fails.
Currently, for documents that are unindexed for example, all that is displayed is:

"indexDetails" : {
 		"db182.coll182.$_id_" : {
 			"valid" : false
 		}

(It doesn't even mention explicitly why the index is invalid: too many, or too few entries)