Looks fine to me.
Pike v8.1 release 11 running Hilfe v3.5 (Incremental Pike Frontend)
Parser.XML.Simple()->parse("<x/>", lambda(mixed ...args){ werror("%O\n",args);} );
({ /* 5 elements */ "<>", "x", ([ ]), 0, ([ /* 1 element */ "location": 4 ]) }) (1) Result: ({ })