What is the complete list of expected JSON responses for DS.RESTAdapter?
Instead of stabbing in the dark, have a look at rest-adapter-test For example, to fill in your question on response data for bulk updates, L738 describes the expected response data: ajaxHash.success({ people: [ { id: 1, name: “Brohuda Brokatz” }, { id: 2, name: “Brocarl Brolerche” } ]});