It is not that it is not important. It is that the description is wrong, and it is not a "small error" when one is describing legal proceedings.  It affects anyone who has an interest in the case.  It matters because anyone who knows what a trial is would think that this is the date when evidence will be presented and the judge or jury will decide whether the state has proven that the defendant is guilty.  On November 8, the judge might make some decisions about the case, or he might just continue it to another day.  The case will not be decided. It is just a hearing, and it might be a very minor hearing in the broad scheme of things.  Calling this a trial is somewhat akin to the little boy who cried wolf. 

Also, the defendant's name is Ryne San Hamel, not Ryan.

Mea culpa, my description as a "trial" rather than a "hearing" may be incorrect.  Why is this very small error important?  How is it significant?  How does it affect the posting?  Who does it affect?  Why does it matter?

Why is h' so concerned?

I think what h' is saying is that the description of the event you have placed on the calendar is not accurate.