Why? There is a very significant weight difference, and the extra power is only available when the battery is not depleted. Which in the onboard lap released, happened before the long straight, so may have been diminished well before. With a flat baattery, the 918 has 608hp in a heavy car.
Sure, 918 has the front axle traction, and that helps A LOT at low speeds. But does the ring has any low speeds? How many second are spent under 100kph, and how much does the 918 there lose by being heavier, and how much down it gain back on acceleration before the next corner?
Above a certain speed, the front wheel drive does not aid in traction, only drive. And it needs (say) 20% more total power to get the same power to weight, while it started on the backfoot with a weaker (albeit N/A) cumbustion engine.
918 did hybrid better than P1 and LF. They put some of the e power on the front axle, and had a bigger battery. Simply a more effective way to go fast with (despite) the additional electric bits.
But this doesn't make a hybrid faster by default.
Imagine the P1 without the (Goodwinn confirmed) 180kg extra for some 180hp? That would be a seriously ligtht car with further improved power to weight. And no burden of depleted battery halfway through the ring lap (that must suck when you're trying to beat a relatively porky Porsche). They couldnhave stuck in a bigger battery, and it would not have helped. Longer braking distance, slower cornering, slower acceleration. Would almost making it around the lap on the battery make up for that? I doubt it. Hybrid bits made P1 a non-winner because they neglected the front axle. And in my opinion, it could have done with wider rear tires perhaps.