By the time it returned in September 1986, his professional relationship with Saward was rapidly deteriorating. Nathan-Turner's lack of first-hand experience in scripting and direction contributed to his tendency to be distrustful of some of the crew around him. Former director-turned-writer Peter Grimwade had agreed to direct Resurrection of the Daleks, but Nathan-Turner removed him from the post -- mainly due to his perception of being snubbed by Grimwade when he did not invite him to a dinner party.
Peter Grimwade
Nathan-Turner