Ember.js restore unsaved records in browser

I have action to rollback changes in controller:

edit:   ->
  @set 'isEditing', true

doneEditing: ->
  @set 'isEditing', false
  @get('positions').save()
  @get('participants').save()

destroyParticipant: (participant) ->
  participant.deleteRecord(participant)

newParticipant: (participant) ->
  @get('participants').createRecord(participant)

cancelEditing: ->
  @set 'isEditing', false
  @get('model.positions').forEach (record) ->
    record.rollback()
  @get('model.participants').forEach (record) ->
    record.rollback()

The problem is, I want to delete the record and after "Cancel editing" to show again this deleted record (because it's still in db).