written warnings

Employee I work with recieved a written warning that was not dated nor did upper management sign this. Employee asked for a copy upon it being placed in file, it was recieved still unsigned and undated. Request was made a month later and stuff was added to that warning with a date and signature...this would make this warning invaild would it not?

[Bricks41]

Not necessarily invalid, but when the employee requested a copy, they were given an undated and unsigned copy? If it turns into a termination situation, the employee could argue that they were not properly informed of the infraction and therefore unable to correct the error in performance.