Hello @catire383 :)
Thank you for stopping by my dear! Well, I sustain that it might have been a visual hallucination. Particularly if your brother was emotional about the passing away of your friend. But, please note, I don't want to claim that the explanations I am presenting here are the ultimate true! As I said this is how neuropsychology explains such occurrences :)
All the best to you my dear.
Have a good evening.