My buddy did exactly the same thing to his new Formula HWR a couple of weeks ago, first time on the water after hitting an alligator gar and going over the front. Wood top and carbon bottom.
It seems as though the impact on the top somehow transfers the energy to the bottom and splits it open. You would think the carbon bottom would not split open from top side impact, but it does.
I have a wood '08 iS 111 and a wood F160. The 160 has taken a couple of nose hits with only a dent/crease not needing any repairs. The iS hasn't taken any hits that I recall.
While the competitive boards need to be light, I also wonder if there is something missing in the carbon layup that make these things susceptible to "popping".
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.