Ah, Maths lives in a world where everything is so black and white!
Absolutely; life (and tax) is then so much easier. Grey doesn't exist in my little world.......nor do i allow it in my clients' world.
I have little doubt that in the real world (which I try and avoid if at all possible) a parent may transfer cash (say £100K) to say the son. The son says "look dad, there may be some tax implications here so let's leave it all a bit vague, no paperwork and see what happens". Dad dies unexpectedly two years later.
Son (having been on an IHT course) says to mum, "look, mum, if dad had given me the 100K it's now subject to 40% IHT (as dad had used his nil rate band) and I (ie the son) have to find 40% of 100k, ie 40K IHT, which as an aside i of course don't have. I think it would be better to treat the 250K as a loan to me; although this doesn't change the IHT charge it is the estate not me who then has to pay it (out of dad's residue)".
Alternatively, dad lives for 7 years after transfer of monies and son says "dad, let's treat it as a gift; then no IHT".
Under either option, with the benefit of hindsight, paperwork is then created and backdated.
In Incredulum's examples, again, i have little doubt that such happens.
However (particularly with large sums), the law will reduce the issue to one of black or white (I like it !); the transfer will be categorised as gift or loan, not some hybrid, for better or worse and woe betide the taxpayer who tries to sit on the fence pending the outcome and gets caught executing a bit of back-dating !!
Incredulum, wouldn't you like to be in my world ??????