"A friend of mine told me a few years ago he and his wife made their wills. In their home and bank accounts they are joint tenants. He went to his lawyer and changed his will and he said his half of the house and his half of the money goes to his two sons after his death and not to his wife. My question to you is what kind of a will is that?"
The short answer to this question is that it's a will that's only going to work if the husband outlives the wife.
In your will, you can only give away what you own at the time you pass away. Though in life this fellow owns a house and a bank account, on death (assuming he is still married) those things will automatically belong to his wife because of the law of joint tenancy. Therefore the will is trying to give away assets that it can't give away.
If the wife passes away first, the will is fine because the husband will have full ownership of the assets on his wife's passing.
I can think of a few scenarios in which a lawyer might draw up a will like this for someone (and I'm just assuming that the lawyer advised the husband about the law of joint tenancy because that is, after all, the lawyer's job). One possibility is that the husband told the lawyer that he and his wife are planning to split the property between them while they're alive so that they are no longer held jointly. Another is that the husband and wife are planning to get divorced and split up their property.
And the third possibility is that the husband mistakenly believed that if he didn't tell the lawyer that assets are jointly owned, nobody would know and he'd get away with it. You'd be amazed at how often clients don't tell the lawyer the whole story because they don't fully understand how legal ownership works. Unfortunately they pay for it big time later on because the document they pay for is not the document they really need.
The worst case scenario for a will like this is that the sons will try to uphold the will, as they will understand it to contain their father's last wishes. This means a lawsuit of course, in which the very assets they are fighting about are being depleted by legal fees, court fees and accounting fees.
Nothing good is going to happen when a person's will does not work together with that person's bigger picture of joint property, beneficiary designation, insurance and family situation.