Was David McDowell a grandchild of Winston Churchill?

It has never been proved, and at this point, there is no way to know with any certainty. Many British tabloids have noted that it is "widely believed" that Winston Churchill's troubled son Randolph conducted a number of affairs during his life, and several of them may have resulted in illegitimate children. But officially, this has always been denied by the Churchill family. David McDowell has claimed to be one of those illegitimate children; unfortunately, at this point, there is little evidence to support his assertion.