Terminating an employee that has raised a grievance

jobbingmusician

Just to clarify - the end of a probation period has no legal significance whatsoever. (And especially in this case, where on the face of it there might be sex discrimination going on.) The only important date, normally, is the two year 'full employment rights' date. But it's already been pointed out to you that for discrimination on the basis of protected characteristics, that date doesn't apply either.