Very standard stuff really.
Employers can easily be held liable what their employees do and say in the name or reference of the company.
Good example is what happend at a previous employers. They were advertising for a position and a friend of someone within the company applied. The said friend asked his friend whether he thought he got the job and got a response from the friend telling him "yep, you got it". (now the friend had nothing to do with recruitment or the position)
Turns out the friend didn't get the job, sued the company for 12 months wages and won!
Another thing that can hold an employer very liable is if an employee accidently (or on purpose) posts market sensitive information? This can lead to some major fines and/or convictions!