Sounds like it worked out as planned, since they're leaving now.
Plus, 40% inheritance tax is crazy. You'd have to sell off half of what you inherit to pay the tax. Sucks if you're a farmer or a multigenerational family business
There are also ways to reduce the tax rate, like through charitable donations.
Like in the US with estate taxes, relatively few people are affected by it.
It's also relatively easily defeated by transferring assets to others well in advance of your death, which is the kind of thing very wealthy people are more likely to be able to arrange.