The "old school" way of trimming the edge of a banknote or any other paper document is to use a rigid one-sided razor blade and a metal ruler. However, there is always a risk involved and sometimes the ruler slips and/or the blade slips. It seems possible, even likely, to me that this is what happened when the upper horizontal edge of the above $5 banknote was being trimmed. Moreover, sometimes when the ruler or blade slips the trimmer has a second "go" in order to tidy things up! In addition, to add to the confusion, some trimmers are left-handed while others are right-handed, and some trimmers trim the note while it's face up and some while it's face down!
Logged
" Buy the very best notes that you can afford and keep them for at least 10 years. " (Richard D. Lockwood, private communication, 1978).