"The site was down most of last evening, at a time when Kurt Eichenwald's story detailing how Donald Trump's company broke the law by violating the U.S. trade embargo against Cuba was being covered extensively by prominent cable news programs. Our IT team is still investigating the hack.""

So many things to comment on here in such a small statement

A: If you get a lot of coverage you get a lot of traffic
B: Legitimate traffic spikes are not a DDOS attack, because they are not intended to bring the site down.
C: You were covered by several major news agencies of course your site got a lot of traffic.
D: A DDOS is not a hack.  It does not achieve remote access to a server.
E: If your IT people blame not being able to withstand an obvious time of high traffic that is legitimate on hackers, fire them immediately.