So, I guess, our overall conclusion from this study isn't completely certain. We wind up with a summary like:
1. The effect doesn't seem to exist for run-of-the-mill fights.
2. When a goon fighter on a goon team fights when his team is down, it seems to benefit that team by 1/8 of a goal, or a bit less than a normal power play.
3. But, that effect isn't statistically significant, so we have some doubts that it's real.
4. And, with only 364 such datapoints qualifying out of around 5,000, only a small percentage of fights match the criterion for that kind of boost.
If you had to reduce that to one line, it might be:
At best, there might be a small effect in certain specific circumstances ... but much, much less than sportscasters make it out to be.
http://blog.philbirnbaum.com/2012/01/do-hockey-fights-lift-teams-performance.html