Comments added on my name, while I was not even logged in to Smartsheet

There is a comment added on my smartsheet. Looks as if entered by me and it shows my name as the user and my name as the commenter. I checked the logs, and the comments.

There is no way I entered that message, and there is no way I logged into system at the time at which I was even sleeping.

How can this happen, what might have happened? Can someone impersonate my as user and add comments on my behalf?