Ah, sorry, yeah. That those double backslashes were an artifact of my logging script which uses Dumper. I'll have to look into replacing that with pp. Anyway, here is the raw output from pp:

  HASH => {
    encoding => {},
    feed => {
      HASH => {
        "author" => {
          ARRAY => {
            HASH => {
              email => { HASH => { "\$t" => {} } },
              name  => { HASH => { "\$t" => {} } },
            },
          },
        },
        "category" => { ARRAY => { HASH => { scheme => {}, term => {} 
+} } },
        "entry" => {
          ARRAY => {
            HASH => {
              "app\$edited" => { HASH => { "\$t" => {}, "xmlns\$app" =
+> {} } },
              "category" => { ARRAY => { HASH => { scheme => {}, term 
+=> {} } } },
              "content" => { HASH => { "\$t" => {} } },
              "gContact\$groupMembershipInfo" => { ARRAY => { HASH => 
+{ deleted => {}, href => {} } } },
              "gContact\$userDefinedField" => { ARRAY => { HASH => { k
+ey => {}, value => {} } } },
              "gd\$email" => {
                ARRAY => { HASH => { address => {}, primary => {}, rel
+ => {} } },
              },
              "gd\$etag" => {},
              "gd\$extendedProperty" => { ARRAY => { HASH => { "\$t" =
+> {}, "name" => {} } } },
              "gd\$name" => {
                HASH => {
                  "gd\$familyName" => { HASH => { "\$t" => {} } },
                  "gd\$fullName"   => { HASH => { "\$t" => {} } },
                  "gd\$givenName"  => { HASH => { "\$t" => {} } },
                },
              },
              "gd\$phoneNumber" => {
                ARRAY => {
                  HASH => { "\$t" => {}, "primary" => {}, "rel" => {},
+ "uri" => {} },
                },
              },
              "id" => { HASH => { "\$t" => {} } },
              "link" => {
                ARRAY => {
                  HASH => { "gd\$etag" => {}, "href" => {}, "rel" => {
+}, "type" => {} },
                },
              },
              "title" => { HASH => { "\$t" => {} } },
              "updated" => { HASH => { "\$t" => {} } },
            },
          },
        },
        "gd\$etag" => {},
        "generator" => { HASH => { "\$t" => {}, "uri" => {}, "version"
+ => {} } },
        "id" => { HASH => { "\$t" => {} } },
        "link" => { ARRAY => { HASH => { href => {}, rel => {}, type =
+> {} } } },
        "openSearch\$itemsPerPage" => { HASH => { "\$t" => {} } },
        "openSearch\$startIndex" => { HASH => { "\$t" => {} } },
        "openSearch\$totalResults" => { HASH => { "\$t" => {} } },
        "title" => { HASH => { "\$t" => {} } },
        "updated" => { HASH => { "\$t" => {} } },
        "xmlns" => {},
        "xmlns\$batch" => {},
        "xmlns\$gContact" => {},
        "xmlns\$gd" => {},
        "xmlns\$openSearch" => {},
      },
    },
    version => {},
  },
[download]