This afternoon on DEV i noticed that passing {quiet:true} to setAttrs ceased functioning, and it was was still causing eventhandlers to fire. This was not happening .. last time I checked (not sure when exactly ), but i know it is not happening in Prod at least as of yesterday. for example, given: somefunction(){ setAttrs({"a":"b"}, {quiet:true}); } on("change:a",function(){console.log("hello world!");}); when somefunction is called, hello world should NOT be printed to the log since quiet is true. And in prod it is not. but in DEV right now it is.