The blanket term of "damage" simply suggests that this was done outside of the mint and was perfectly fitting. However, in this case, yes... someone most certainly did it, likely using scissors/tin snips or the similar.
The other side probably has the same or flat damage. Like from shrub clippers /anvil clippers. FYI, if you can't find the "error" online then it probably isn't an error. There is an unlimited type of damage a coin can take. Though only a limited amount of "errors" that are produced. I also don't recall a website listing damage ... which would be endless ...
Had a kid come to my house not long ago. He was selling knives. Wanted to show me how tough his scissors were and did exactly this to a poor defenseless cent. Yes, this is damage.
Ok well since that did not work guess the 1977 d with lower case o instead of capital O in United States of America
I know that was damged but now I got the 1977 d penny with the o not capitalize on back of coin so I am feeling a little better!