This happens more than you would think. The mistake is probably compounded by two designs being almost the same and potentially the same engineers involved. I'

This happens more than you would think. The mistake is probably compounded by two designs being almost the same and potentially the same engineers involved. I'll bet the supplier searched for the engineer's name in his inbox and responded to a big email thread about the project with many people involved. The Otto engineer's old colleagues got the email instead of him.