No, a union protects employees from their employers' employment action (e.g. suspension, demotion, termination).
Punnet Square of typical unions (forgive my formatting as tables are not supported on Lemmy:
+============================+======================================+==========================================================+
| | Employee broke policy | Employee didn't |
+============================+====================================================================================+============================================================================================================================================+
| Union successfully defends | Fellow employees and/or employer and/or customers upset, likely zero news | Employer upset, almost certainly zero news |
| Union fails to defend | Employee suspended/retrained/terminated appropriately, almost certainly zero news | If local news is lacking in Florida Man stories, they might run it between dick pill and truck ads, but 99.999% of people never hear of it |
+----------------------------+------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------+
Contrast that with law enforcement unions:
| | Employee broke policy | Employee didn't |
+============================+======================================+==========================================================+
| Union successfully defends | Justified public outrage, viral news | (Likely secretly) unjustified public outrage, viral news |
| Union fails to defend | Justified public outrage, viral news | Few know, and fewer care |
+----------------------------+--------------------------------------+----------------------------------------------------------+