Rule action seems to fire unexpectedly
Your problem is node_unpublish will be saving the node, triggering the second rule on node_update--article thereby actioning mimemail_to_users_of_role

Looks like you'll need to add a condition to make sure the email should be sent. For example, you could check the updated node is not being set to "unpublished"

"IF" : [ { "data_is" : { "data" : [ "node:status" ], "value" : "1" } } ],