The employer argues that the employee's high blood pressure is not a disability warranting accommodation, and it has no obligation to accommodate the employee because he lives with his elderly mother.
As to the latter argument, the employer is likely correct—it doesn't have to accommodate an employee because of the employee's association with someone with a disability, even if that family member falls into one of the COVID-19 high-risk groups.
I also think, however, that this employer may have issues with the denial of the employee's work-from-home request for his own alleged disability. It's possible that this employee was entitled to work from home as a reasonable accommodation. We don't know, however, because the employer never asked for any medical information from the employee as to the need for the request. According to Tchankpa v. Ascena Retail Group, "Employers are entitled to medical documentation confirming the employee’s disability and need for accommodation." If on-site attendance is presumed to be an job essential function (as noted by the Tchankpa court) then an employer would have to consider offering an accommodation to meet that essential function. Telework might be one such accommodation. But the employer won't know that unless it engages in the interactive process with the employee. And that's where this employer failed. The employee asked for an accommodation and the employer refused it without consideration and without gathering the necessary information from the employee.
So, yes, you might be able to deny an employee's work from home request. To be clear, in most cases I don't think you should. But it is possible. You just have to do it the right way, which will always include the interactive process to determine if the employee is disabled and if the request is medically indicated to permit the employee to perform the essential functions of the job. For high-risk employees with a doctor's note, however, denying the request takes a huge legal risk.
* Photo by Chris Montgomery on Unsplash