With such an odd disappearance I'm sure they are considering all possibilities. However, to date, we don't have any indication of a crime having taken place. Nothing.
Amateur opinion and speculation
She is not here anymore and He is... That is a Fact...
She did not fall off a boat in the Atlantic..
How this happened in RT own words is virtually impossible, in my opinion.
But I do consider it an accident. It was my first thought that she dropped of a heat stroke..
Giving RT the benefit of the doubt and treating him as victim.
Closing my eyes to 80 SAR people including specialists and air support.
I will go check the possibility on my own feet with all Prayers in place that he is correct.
That is as fair as anyone can be.
It should be looked at with a good attitude.
Positive attitude to find Barbara Thomas.
But to be blind to all that is possible is foolish ...
You must be street smart because people are what they are.
There is good in our world and there is evil..
jmho