I'd gamble and take the first option. He has a 70 to 79 percent chance of getting to HNL on time on that flight, according to DL, so the odds are in his favor. If he's sitting near the front of the SEA-HNL flight, it'll save him some time, too. The HNL airport site says the bus to the interisland terminal takes 10 minutes, and I'd say that's about right. If his carry-on isn't too heavy, walking might amount to about the same amount of time. And there are few interisland flights left at that time of night, so he won't be tangling with big crowds. I wouldn't buy the higher-fare ticket on Hawaiian, instead getting the cheapest fare and planning on making the flight.

If everything goes wrong, you can apply the Hawaiian ticket to another after paying a $30 change fee (http://www.hawaiianair.com/changeflight).

A few weeks ago I flew Go Mokulele from LIH and connected with a DL flight at HNL with 1 hour and 15 minutes between flights and had loads of time.