is there such a thing as writing in unknown language/dialect after having a strong spiritual encounter with Christ?

1 year ago my father-in-law, who has Parkinson's disease, almost drowned when his boat sank. It was an absolute miracle the way the rescue transpired and 3 days after his rescue and recovery, he started writing in an unknown language/dialect that is totally legible and he writes from left to right and without any thought going into it at all. He can fill a notebook page up in a matter of minutes and there are recurring symbols/letters, 7 lines with 9 characters in each line before skipping a line for another set of 7. We have had an Archaeologist and language experts to look and so far, no luck at all in figuring it out. He can barely print his name where you can read it from his shaking right hand but when he starts this unknown writing, it flows smoothly, very neat and legible, without concentration or thought but isn't recognized by anyone as a language/dialect. Has anyone ever heard of this type of scenario or an example of this? Once again, this only started 3 days after he had a physical and spiritual encounter with either an angel or Jesus Christ. He was in the water for 3 hrs trying to swim back to shore at night after his boat sank. The water temp was 69 degrees and he only suffered from hypothermia and was in the hospital for 8 hrs. He now says that was his official Baptism and is definitely a changed man. Any ideas?