This is a very interesting piece of evidence. I would not say it is proof. Proof would need to show that there was no other cause for the change other than the entity that was contacted. There is not enough information given to effectively show proof. What else was happening with the company that caused them to change their timeline? Could be any number of things. What this does show is that there may be some kind of correlation between the ritual to contact the entity and the change in the company.
Now, do I believe that it worked? Hard to say. I wasn't there when it happened, nor have I spoken to the entity involved. I certainly believe it is possible, and his experience sounds similar to ones that I have had when doing simular works. I feel that the person was honest in his description. I do believe that it worked for him. Unfortunately proof will never be there so that we can convence skeptics that these things are real.
Now, the next question is "Is it safe?" By his own admission his child was almost seriously injured or killed by something that may or may not be connected. Also, what changed to cause that result to occur? Maybe the opportunity to have improvements done was taken away from someone else? Whose need was more urgent? I'm not saying that the person doing the work should or should not have done it. I'm just wondering if these things were taken into consideration. There is no mention of them, abd he does not state in his request that he wanted it completed with no harm to anyone. Then again, he may have. Another case of not enough I formation.
Like I said, it is really good evidence. I like it.