Yes you are. In fact you can also view some third channels while recording two.
If both recordings are from the same transponder (eg BBC1-HD & BBC-HD) then you can watch any other channel (and live pause it). When one of the two recordings finishes you can even record the one you are watching from the timeshift buffer.
If recordings are from different transaponders you can watch any 3rd channel sharing a transponder with either recording.
At a guess the poster only had one working cable so only one tuner connected.
Welcome to the forum.