An add operation should result in an ADD ChangeAction occurring in all the models. But the MemoModel and AddressModel tend to always emit CHANGE events. Also the object then ends up not being set for these operations.
This is not reproducible in the program but more of a code issue
Since its a code defect all environment suffer from it.
Emit appropriate event based on the action since in the future it may make sense to hook these operations for future features.
Example (requires code to reproduce)
1. Setup a listener on the relevant model.
2. Do an add operation (it will always get the change event and the object passed will be null)