Plot hole: Why would Sian let Griff into the shower room if she broke up with him the night before?
Factual error: The stratagem used to conceal the murder and disguise it as suicide is absurd from the start; it relies on the old trope of a gun "silenced" shooting through a pillow. It simply does not work, a gunshot in the early morning in the empty camp would have not been dulled down significantly by a pillow, and still be heard.
Plot hole: The shower room door has a lock, that as shown in the denouement the killer never closed - making it fairly obvious that the victim did not lock herself inside the room to kill herself. Another minor but still significant problem with the stratagem used; the killer shot the girl in the chest; even if they didn't do any gunshot residual test on her hand, the trajectory of the bullet still would have proven the impossibility of a suicide.
Continuity mistake: DI Goodman is inspecting the pillows; when he gets to the second bunk bed, you can see that handling the pillow he accidentally catches with his arm a blue piece of clothing placed on the railing, dragging it a little along the way, towards the vertical support bar. The next shot is evidently from a previous take, because that blue rag is in the initial position, away from the bar. (00:39:10)
Continuity mistake: When Goodman sprints away from the banquet, the cue cards in Dwayne's hand move from both hands to a lowered left hand in the faraway shot. (00:38:40)
Continuity mistake: When Goodman jumps up yelling "yee-haaw!" messing the wedding table, Commissioner Patterson grabs a towel with his left, but at the cut he is using the right hand to clean his left. Likewise, Florence has in the second shot a hand on her chest, but she didn't have that pose already in the previous, it was just her initial reaction. (00:38:00)
Continuity mistake: Humphrey gets next to Leo's bed saying "Hey sexy." He has a hand in his pants and the other on the phone, but they swap place at the first cut. When he gets up and protests that he loved Sian, the phone disappears. (00:39:10)
Continuity mistake: After hearing about the theory that perhaps Sian and her knew each other from back home, Perrie Campbell walks away. Goodman grabs the manuscript from the table, but his arm does not move in the reverse shots. He then puts it back, but when it is his turn to stand up, it is nowhere to be seen - yet it didn't look like he could have put it back much far away. (00:16:55)
Continuity mistake: When Perrie Campbell says "Now I can see it", about the world out there, the bang on her right side is windblown. The wind is instantly absent in the next shot, just as in the rest of the shots from that angle. (00:16:35)
Factual error: When JP shows the article from the Cowbridge Gazette, it is the Wednesday 22.01.16. January the 22nd was a Friday in 2016. Following article's date; Wednesday 2.2.2016. Actual 2.2.2016: a Tuesday. (00:15:25)
Continuity mistake: Dwayne has his fingers on a different spot of the evidence bag with the ecstasy when the camera angle changes. (00:15:05)
Continuity mistake: Humphrey brings attention to the toiletries when asked why does he not quite believe it was suicide; in close-up the bag is in shadow, but in the wider angle there was direct sunlight on the top of the bottles. (00:05:45)
Continuity mistake: When Perrie Campbell tells her much younger friend that she can still drink her under the table, a bottle of beer suddenly appears in her hand. During the rest of the exchange the beer bottle in Sian's hand faces different directions each shot. (00:01:05)
Continuity mistake: During the first scene, Sian Evans' hand is around the bottle of Etensel or flat on the table, depending on the angle. (00:00:45)
Continuity mistake: At the beginning of the episode, Perrie shows the moth tattoo to Sian. In the close-up of the lepidoptera, Sian's elbow is barely off the corner of the table, but she's leaning with just the hand in the following shots. (00:00:40)
Answer: There's probably no particular reason. Sets and props on long-running TV shows often change as needed and for various reasons throughout a series run.
raywest ★