I am just reading back through Tony Hurley's evidence. It is more messy than I thought ( the situation I mean, not his evidence ).
I think the wording of Helen having produced an Interim Will was misleading.
An Interim Will would have been signed and witnessed and would have been her Final Will. All legal.
What it sounds like now, on a read back, is that she had drafted out a Statement of Wishes, which she drew up * in the interim * while she decided who got what.
A draft is a draft, wishes are wishes. Not legally binding and can be challenged.
The only good thing I can see in all of this ( if the above is correct ) is that
IS cant inherit anything - forfeiture law
take him out of the equation and Helen's draft of wishes is likely to match her 2012 Will, which would stand as her last legal Will.
So in the end, I think brother and step children will inherit, which is what Helen would want.
I don't have the same impression, I think Helen had a full binding will which left her entire estate as a discretionary trust with the trustee being Tony Hurley - https://www.blakemorgan.co.uk/training-knowledge/guides/client-guide-use-discretionary-trusts/
Hence TH being shocked that she had total faith in his judgement and the defence claiming that TH could have left IS without a penny. Which he wouldn't have done, if Helen had had a natural/accidental death as she had left informal but clear guidance on what she wanted done.
I'm pretty sure the plan later was to go back to a standard will with bequests, which IS wanted to avoid.
I also expect that given the situation the estate will still go into a discretionary trust and TH will be left with the "fun" of deciding who gets what. I think the Stewart sons will pose a dilemma for him - Helen clearly saw them as family and there is no evidence or indication that they had any idea what their father was doing/has done.