Ask HN: I'm a New Manager – How to Best Handle Employee Grievance?

I was recently hired as a Project Manager at a small company. I've only been on the job a few weeks when I was told an employee had filed a complaint against me for creating a hostile workplace. When I asked how I exactly did this I was told I said a curse word at a meeting.

Has anyone ever dealt with this situation before? What is the best thing for me to do? I dont want a hostile workplace environment on my end where I have to keep looking over my shoulder either.