What version of git-annex are you using? On what operating system?

5.20151116+gitg5416a1a-1~ndall+1

Please provide any additional information below.

    "backend usage": [
        [
            "MD5E",
            2
        ],
        [
            "SHA256E",
            2
        ]
    ],

instead of more logical

    "backend usage": {
         "MD5E": 2,
         "SHA256E": 2
    }

also it seems it just doubles them since I have only 2 files, 1 for each backend (as reported also by info "local annex keys": 2).

fixed --Joey