Despite increases take-off thrust, acceleration slowed significantly, which may be explained by the appearance of additional braking force.
As I said before, the brakes being on would explain this crash. The only thing burning in the lake, was the wheel bogey, which would be better explained by very hot brakes than a fuel spillage. And that slowing of the aircraft after 210 kph again looks suspiciously like brake application.
Perhaps the brakes came on accidentally. Perhaps the f/o thought they were too far down the runway, and decided to unilaterally abort the t/o by applying the brakes. (Would not have been the captain, as he was calling for full power.).
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