Kubica was running third in his BMW but had closed in on second-placed Sebastien Vettel so quickly that Theissen confidently proclaimed his driver "had the race won" if he had not crashed out three laps from home.
His theory was all in the tyres — but was he right?
In the closing laps, Kubica was the only one of the leading three drivers on the harder option tyre, which is a long lasting and consistent tyre compared to the super soft option, which is fast but deteriorates much more quickly lap by lap.
Theissen's theory was that if Kubica had managed to make a clean pass on Vettel, he would have had three laps to chase down the leading Brawn GP car of Jenson Button.
At that point, Button was four seconds ahead and both he and Kubica were running in the low 1:29s. But Button was more than half way through the life of his super soft tyres and, from the data BMW had to hand on the pit wall, his tyres were going to get worse and worse (and his car slower and slower) from that point on.
Kubica, on the other hand, had hard tyres that would run consistently to the end.
The suggestion initially stacks up.
BMW had noted that when Kubica was running on soft tyres, at the start of the race, he lasted 12 laps before having to change and the difference between his best lap time on that stint (set on his fourth racing lap) and the last full lap he completed on those tyres before coming into the pits was 3.2 seconds.
That happened in conditions at the start of the race, which were different to the conditions at the end — but in the final stint of the race, Nick Heidfeld in the second BMW was on the super soft tyres so BMW could directly see what was happening to their super softs.
By the time the Kubica-Vettel collision happened, Heidfeld had done 11 laps on his super soft tyres and since his seventh lap on the tyres he had been setting lap times around three seconds slower than the fastest lap he had done on that set.
His tyres clearly matched the deterioration experienced by Kubica earlier in the race, and BMW concluded that Button was about to start losing time to Kubica at a rate that would have allowed the BMW driver to catch him and then overtake - even, as it has been pointed out, without the help of KERS.
But the Brawn GP car was different. Button was on his eighth lap on the super softs and, unlike Heidfeld, his times did not suggest that the Brawn was suffering the same tyre deterioration as on the BMW cars.
He was still only four tenths of a second slower than his fastest flying lap on that set, and had posted consistent times throughout his stint.
This consistent running on the super soft tyres went against the trend for the rest of the grid — and the fact that Button's fastest race lap was set on the harder compound, when half the cars running super softs at the end of the race set fastest times in that part of the race, suggests that Button was deliberately going slower to conserve the car on that final stint.
So despite Theissen's optimism, Button would still have had enough speed in the bag to stay ahead to the end.
Heidfeld on Super Softs:
1st flying lap 1:29.421
2nd flying lap 1:28.968
3rd flying lap 1:28.283
4th flying lap 1:28.373
5th flying lap 1:28.697
6th flying lap 1:29.476
7th flying lap 1:31.178
8th flying lap 1:31.204
9th flying lap 1:31.444
10th flying lap 1:31.730
...safety car
Button on Super Softs:
1st flying lap 1:29.395
2nd flying lap 1:29.576
3rd flying lap 1:29.296
4th flying lap 1:29.868
5th flying lap 1:29.497
6th flying lap 1:29.807
7th flying lap 1:29.636
...safety car
DATE PUBLISHED ON: 31 MARCH 2009