Not one but 2 large impacts? The coincidence sounds like evidence for the Nemesis theory. See http://en.wikipedia.org/wiki/Nemesis_(star) for more.
The Nemesis theory says that every 26 million years Nemesis arrives and knocks a bunch of stuff out of the Oort cloud. Most of it is swept up by Jupiter, but the Earth goes through a period where large asteroid impacts are likely. It is a much smaller coincidence to have 2 large impacts in a period where large asteroid impacts should be common.
Therefore this result is more substantially likely under the Nemesis hypothesis than it would be without the Nemesis hypothesis. Which implies that the conditional probability of Nemesis given this observation is higher than it would be without this observation. Which is a fancy way of saying that the observation is evidence for the Nemesis hypothesis.
There are other hypothesizes besides Nemesis to explain the supposed periodicity of impacts. Essentially, we need something to cause a gravitational change to the Oort cloud. Other possibilities include Brown dwarfs and black holes or precession in the rotation of the milky way.
More precisely it is evidence that something caused excess asteroid activity 65 million years ago. And therefore is supporting evidence for any theory which could explain that. Nemesis is the best known possibility, but is far from the only candidate.
I was saying that it is evidence that the dinosaur asteriod was not just a random asteroid. Some external force disturbed potential asteroids and shoved multiple ones into the inner solar system. That fits with Nemesis. But would fit with other theories as well.