The save_fields_for_post() method in the post context has a guard condition where it checks the post ID before saving data to it. This is for the situation where another post gets updated when a post is saved and prevents meta data being saved to another post. Ref:

This was introduced in #147.

There is no such protection for terms. If a term gets saved and some code updates another term, Fieldmanager will write its term meta to that term too. Ref: