Towards the end of the episode, Jonathan and Carla discover that the tree in the woods now has four holes in it that were not there previously. The holes are made by a garden fork being pushed through the torso of one of the characters as it turns out, yet there is no evidence of any blood of any kind, either embedded in the holes (as there would surely be) or anywhere in the vicinity. Considering the method of murder, the fact that the victim was attached to the tree for some time, and the subsequent hiding of the body, blood would be everywhere.
The timeline is definitely off in this episode. Carla is invited to dinner by Fell and arrives as the sun is definitely going down. In the next scene we see Jonathan, Adam and the reporter in the park where Adam is being 'crucified'. It is obviously no later than mid afternoon. Jonathan is warned what the reporter has seen and rings Carla at Fell's. By now it is lateish night and they have just finished dinner.
Geraldine Vaccaro turns up at the site of the boat accident, and then at Justin's house, after 'the news comes through' about his death. Yet she was his secret lover; neither Mickey nor Ashley knew who she was, so couldn't have contacted her. Even if it had been reported on the news in the US, which is highly unlikely, she wouldn't know the exact spot he died. And since she sent the fax through saying 'talk to you tonight' wouldn't she think it strange immediately that she didn't get through with her good news?
Mickey brings in a huge pan/cauldron of freshly-cooked pasta and pours it into a bowl, then takes it out again. At no point is he using any oven gloves. Given it's a proper pasta cooker, even allowing for the draining off of the food, it would still have been too hot to transport with bare hands.
A major plot point is that Geraldine and Justin had a secret word that they had arranged to tell to each other, should they be able to communicate after either of their deaths to know that the communication was real. Geraldine is given the opportunity to ask five questions to Justin by the gypsy woman who is supposedly in contact with him. Why wasn't her first (or any) question on their first meeting "what is our secret word"?