Robocopy log file: Extra dir and an improbable match -

i have executed following command:

robocopy.exe /e /zb /copy:dat /r:5 /w:7 /tbd /np /tee /log:

the intended file copied, along other files had exact same name , residing in folder beneath source directory. appeared in output:

options : /tbd /tee /s /e /copy:dat /zb /np /r:5 /w:7

*extra dir -1 \computer\path\to\file

new dir 0 \computer\path\to\folder

new dir 0 \computer\path\to\folder

new dir 1 \computer\path\to\folder

new file 1.5 m filename

-output trimmed-

            total    copied   skipped  mismatch    failed    extras  dirs :        15        14         1         0         0         2 files :         4         4         0         0         0         0 

1. i understand *extra dir stands for: “extra” file present in destination not source. can explain -1?
2. two folders copied destination, without either of them containing file specified in command, or file name in path. not empty in source folder copied empty. why folders copied?