Professor John Mee:

Survivorship is outside the will. Imagine that there was never any murder and 20 years later one of the couple dies. The dead person's share is automatically extinguished and the other person's share becomes everything. That does not happen by virtue of a will: it happens automatically because of the nature of the institution of the joint tenancy. It is a key point. If two people are joint tenants and we were to ask "who would die first?" the answer is that we cannot know. In Cawley v Lillis Ms Justice Laffoy commented that one cannot tell which joint tenant would die first and that it was one of the "imponderables" of the case. The other key point is that when the estate is not land anyone can sever at any time without permission from the other person. They can go to their solicitor and make a deed that has nothing to do with the other person. Outside of land it is hard to see how a killer would benefit because instead of murdering the other person he or she could just achieve it automatically, in an office and without permission from the other person. This is partly what has motivated other countries. A person could get there any time that he or she wanted. The land situation is unusual because with section 30 one cannot sever the joint tenancy oneself. Ms Justice Laffoy also felt that this problem is special with regard to land. The equivalence is not so obvious anymore. Instead of a man murdering his wife in a terrible way, for example, he could just have severed the joint tenancy and had the same result with regard to benefit and it did not really seem like profit. With land, however, one could not do that. On the other hand if the person refused to sign, one could have asked the court and the court might have allowed the severance. It is very hard to pin it down.

Section 30 is a very strange provision. Let us consider two adults, say they are both 30 years old, and one wants to sever the joint tenancy but the other says "No because I think you are going to die first.". The first person might ask "Why would you think that? Please agree to sign.". The other person still will not and the case goes to court with the first person saying the other is unreasonable. In my submission I suggested that the best one could do was to look at it to see if the court would have allowed the severance if the person had asked for it instead of committing a murder. If the court would not have allowed it then we would try to think what benefit has the person got from achieving the severance. There would be an element of actuarial calculations while the court tried to work out what benefit had been achieved and tried to undo that. This is the best I can think of.

The problem is caused by section 30 being an unusual provision.