I make no guarantees this doesn’t break something else, but for me it seems to work correctly if I make Feediron_Json::format() skip carriage returns:

$ git diff
diff --git a/Json.php b/Json.php
index c988962..fc7f554 100644
--- a/Json.php
+++ b/Json.php
@@ -8,6 +8,7 @@ class Feediron_Json{
                $strLen      = strlen($json);
                $indentStr   = '    ';
                $newLine     = "\n";
+               $cReturn     = "\r";
                $prevChar    = '';
                $outOfQuotes = true;
                $currentline = 0;
@@ -30,6 +31,9 @@ class Feediron_Json{
                                $currentline++;
                                continue;
                        }
+                       if($char == $cReturn){
+                               continue;
+                       }
                        if($char == ' ' && $outOfQuotes){
                                continue;
                        }

(Using PHP 5.6.30 here.)