I agree with comments above, but would add that you haven't provided their termination dates. If it's a small company, odds are pretty good that they didn't sell the company and step out the door, never to return. It's not hard to make a case that they did something thru the end of the year and term'd Dec 31 or later.
As noted, it is important to know whether it is an asset sale or stock sale.
If it was an asset sale, then the old company might have existed for some time after the sale (and that is where it is easy to justify employment thru the last day of the year). If it was a stock sale, well, then the new owners would be footing the contribution bill so you want to be darn sure that everyone knows the implications of the termination dates.