Description of problem:
Defect is reproducible for both API and Hammer CLI.

API:
Attempt to update product with new organization gives no error, but actually no changes happened:

Making HTTP PUT request to https://my_server/katello/api/v2/products/72 with options {'verify': False, 'auth': ('username', 'pass'), 'headers': {'content-type': 'application/json'}} and data {"description": null, "label": "f44252c2-a057-4ae6-a2c7-9ca26a17e999", "organization_id": 106, "sync_plan_id": null, "repository_ids": [], "id": 72, "gpg_key_id": null, "name": "test_name"}.

Received HTTP 200 response: {"sync_state":null,"last_sync":null,"last_sync_words":null,"organization":{"name":"org_name","label":"2f2e7855-c46a-46cf-b160-f51f3864fbf4","id":105},"id":72,"cp_id":"1456057498035","name":"test_name","label":"f44252c2-a057-4ae6-a2c7-9ca26a17e999","description":null,"provider_id":207,"sync_plan_id":null,"sync_status":{"state":null},"sync_summary":{},"gpg_key_id":null,"redhat":false,"repository_count":0,"":null,"created_at":"2016-02-21T12:24:57Z","updated_at":"2016-02-21T12:24:58Z","product_content":[],"available_content":[],"permissions":{"view_products":true,"edit_products":true,"destroy_products":true,"sync_products":true},"published_content_view_ids":[],"readonly":false,"repositories":[],"provider":{"name":"Anonymous"}}

For that specific example id should change to 106, but that fact doesn't happen

CLI:
Create new product:
hammer -u username -p pass product info --name my_prod --organization-id 102
ID:           70
Name:         my_prod
Label:        my_prod
Description:  
Sync State:   
Sync Plan ID: 
GPG:          
    GPG Key ID: 
    GPG Key:
Organization: org_name
Readonly:     false
Deletable:    
Content:

Attempt to update product
1) Unexpected and non-informative message:
hammer -u username -p pass product update --id 70 --organization-id 103
Could not update the product:
  Missing values for product.
2) Found way to run command at all, but organization was not updated as expected
hammer -u username -p pass product update --id 70 --name my_prod --organization-id 103
Product updated
hammer -u username -p pass product info --name my_prod --organization-id 103
Error: product not found
hammer -u username -p pass product info --name my_prod --organization-id 102
ID:           70
Name:         my_prod
Label:        my_prod
Description:  
Sync State:   
Sync Plan ID: 
GPG:          
    GPG Key ID: 
    GPG Key:
Organization: org_name
Readonly:     false
Deletable:    
Content:

Version-Release number of selected component (if applicable):
6.1.7

How reproducible:
Always

Steps to Reproduce:
1. Create product assigned to organization
2. Attempt to update product and assign it to another organization

Actual results:
Product is not updated

Expected results:
Product updated successfully

Additional info: