Like most medical marijuana patients, Christine Callaghan probably didn’t realize that using “legal” marijuana could have serious consequences even though it is no longer a criminal offense in her state.

AP reports that Callaghan, a Rhode Island graduate student represented by the ACLU, sued Darlington Fabrics Corp. and its parent company.

Carly Iafrate, the attorney who filed the lawsuit for Callaghan, said if employers are allowed to discriminate against medical marijuana patients, then its legalization would become “an empty promise.”

“People with disabilities simply cannot be denied equal employment opportunities on the basis of the type of medication required to treat their particular condition,” she said.

Callaghan, who uses medical marijuana to alleviate the symptoms of migraine headaches, sought a two-month paid internship at the textile company for the summer after it was arranged by one of her professors. During her meeting with Human Resources, she disclosed her medical condition, explained that she had a medical marijuana card permitting its use, and told them she would not bring marijuana to work or use it before work.

Rhode Island has had statutes authorizing medical marijuana since 2006. Unlike some states, Rhode Island’s statutory scheme provides some protection for employees.

R.I. Gen. Laws § 21-28.6-4(c) provides: “No school, employer or landlord may refuse to enroll, employ or lease to or otherwise penalize a person solely for his or her status as a cardholder.” Rhode Island’s medical marijuana statute is required to be interpreted liberally to effectuate its purposes. (R.I. Gen. Laws § 21-28.6-13.) One of its purposes is “to protect patients with debilitating medical conditions, and their physicians and primary caregivers, from arrest and prosecution, criminal and other penalties, and property forfeiture if such patients engage in the medical use of marijuana.” (R.I. Gen. Laws § 21-28.6-2 subdiv. (5).)

The statutes do not permit people who are actually under the influence to operate a motor vehicle or require an employer to “accommodate” the medical use of marijuana in the workplace. (R.I. Gen. Laws § 21-28.6-7.) Policy makers also wisely made the choice to make clear that as person is not considered to be under the influence “solely” because there are marijuana metabolites in his or her system.

Although the company’s lawyer, Timothy Cavazza claimed that the company is “confident they acted in compliance with state and federal law and that the lawsuit would be dismissed,” it sounds like bluster.

First, it’s absolutely clear that no one who uses medical marijuana has any federal claim against their employer as long as marijuana remains illegal under federal law. Although I haven’t seen the suit, I’m reasonably sure the ACLU aren’t making any federal claims, making that part of Cavazza’s statement irrelevant.

The issue is going to be whether they complied with state law, and there’s a good reason to think that they did not; Iafrate is right: an exception to the law allowing employers to discriminate against people who use medical marijuana on their own time and in their own home would swallow the right altogether.