Buying a bike from a deceased estate

Hi, I am looking to buy a bike from a dead guy. Passed away six weeks ago, I had a look at it today. License has just expired. What are the potential pitfalls if one buys from a deceased person or from his estate? Nedbank is the executor, brother in law is handling the sales. Any advice is really appreciated as I have no experience with this. Cheers Lars 084 3829505