Under current U.S. law, the employee is at will, and can be discharged for any reason or for no reason..It does not matter that the employee was accused of something that was not true (smoking marijuana).

If you were the HR manager of Diana's company, what would you tell the employer about the wisdom of his action?Would you recommend that he rehire Diana?What would be the pros and cons of that?Or what would you suggest he do next time he suspects an employee of marijuana use?

Do you think the law should be changed, and if so, how?For instance, if Diana could prove she was not smoking marijuana (by taking a drug test), should she have a legal right to rehire?

Or, if she was union represented, how would her situation be different?

And finally, would/should any of what you recommend change if Diana lived in a state in which recreational use of marijuana were legal?