Learning on someone's wedding day is not the time to be learning how to use flash. Learning flash after you've been hired as someone's wedding photographer should not be the time you should be learning flash. I don't get this idea that people have that weddings are easy and fun. They are a lot of work and very time consuming to be something you do just for "fun". They're also where you're going to get sued if you screw something up.
I don't think its rude for professional wedding photographers, who trained and have worked hard to learn their trade, to be a little put off when someone doesn't even know the basics and wants to shoot weddings.
Nor do I. I also feel the same way. What I said is what is done is done. I think with Practice (Before wedding date) she can pull it off satisfactory. I also believe as established wedding photographers, they should do more than scold her when it is already set and a done deal. Mistakes were made obviously, but it doesn't change the facts.