Yeah I think watching it before making too many comments might be an idea. There were no wild accusations made, at least not in part one. The people in the show simply noted that at around the same time (97/98-on) and around the same place (NE Tas) the following events occurred:
1. Oysters in the St. Helens area (is it Georges Bay?) began dying after rainfall events as well as suffering deformities in general.
2. The local GP noticed an unusual amount of unusual cancers in the community.
3. The Devil Facial Tumour Disease was discovered and took off in the north east.
4. Plantation forestry in the catchment area increased greatly.
They prepared a report stating nothing but this (hypothesising there was a connection) and requesting scientific testing be carried out. The government shot them down in a big way, with apparently no reason.
The people in question then funded scientific research themselves. The only results that have been mentioned are that they found the water in a river (not sure which) is toxic, even with summer flows. Something they did not expect to find.
They have not accused forestry as being to blame, simply noted that the problems mentioned above have coincided with increase plantation activity in the catchment, and that the largest oyster kill occurred not long after the aerial spraying helicopter crash mentioned above. None of this is really questionable; it is like stating water is wet.
Personally I would have liked to see more data, such as:
1. Have similar problems occurred with oysters around the world?
2. Do the unusual cancers in people constitute something statistically significant, or is it a nation wide trend or likely to be coincidental?
3. The current state of play with DFT research.
4. How much extra plantation forestry are we talking about? Millions of hectares or what?
It certainly isn't a conclusive portrayal of how forestry is ruining the rivers, but nor is it a so called "beat up". We will see in part 2 if it becomes either. After all, the prelude did say that they find the opposite of what they were expecting. Until part two has been televised I withhold my judgments on the show and the issues involved.
(Perhaps the oysters are poisoning the river and causing the trees to die so they have to be sprayed? Perhaps the DVT has got in the water then mutated and affected the oysters? Perhaps a DVT infected devil got in the helicopter and attacked the pilot thus causing him to crash? Perhaps the chemicals used in plantations are causing issues as is hypothesized? As yet we don't know and the people involved simply request the government to look into it

)