There's a long article in Yeshurun about it. IIRC Rav Elyashiv and the 9/11 Bais Din (Rabbis Eli Ber Wachtfogel, Eliyahu Levine, Avremel Bromberg) held it was a siman. The lomdus of the shaalah is - if DNA is 100,000 simanim baininim and if so can't be used for Aguna, or is it one big siman muvhak and can be used.
That's not the case here. This is an almost frozen, intact body with (almost?) all identifiable features,
in his own car, within his city less than 10 days old.
(This is not a man out at war in the desert after 6 months of disintegration in the heat with DNA molecules as the only 'survivor'.)