I dont see how Billy can not be suspended if not sacked.
I am wondering if the actor has said he wants to leave the series so they have created this whole series to give him a big send off (in terms of time on screen and being central rather than tea makers).
But still think the main fault with the series is the writing is so poor.
If the knot is meant to be a clue, its pretty crass as anyone one growing up in Shetland with a fishing family would know that.
So why would him using that knot implicate him?
If there is evidence from the past, before his brother and the other man were lost at sea, they he was helping them with their drug smuggling that would be a bit more credible.
Also, how come no one was aware they were smuggling drugs in such a close community.
Or that they had smuggled in the one haul lost at sea and later retrieved fetched enouhg money over years that all the unused money kept coming in?
Or someone took over the business, and as the "poet" had distanced himself from the family it cant be him.
I think it is pointless going on about Tosh, this is the writers.
Although I can see given her involvement with her work colleagues that is must be really hard.
And who would you go to?
But as others have said, through all series of Shetland the police, whichever character had bent the rule for friends etc..
Accept Billy. Or so we thought.
He must be being written out.