A few assertions would have also stopped this.

    During buildup of the our_id list: assert (vimeoId not in our_ids). 
    After creating the list:  assert len(set(our_ids)) > 10000 and assert len(set(our_ids)) == len(our_ids)
    Before each final deletion: assert id not in hardcoded_list_of_golden_samples. 
    Depending on the speed required you could hit the api again here as an extra check. 

But as always everything is obvious in hindsight. Even with the checks above, Plan+Apply is the safest approach.