I don't quite understand how that works (below). Maybe I'm not looking at it in the right way.
FFIND numbers lines starting at 1. The "^r^n^r^n" is in there, but the first half of it is at the end of line 3 and the second half is on line 4. I don't know why it's found at all and why FFIND reports line 4 (and I'm not complaining about either behavior).