Thank you all for your answers, I really appreciate :)
It's seems by the answers I got here and on another forum that the drill hypothesis is unanimous! I was fooled by the visual illusion of the pictures thinking both sides anomalies were raised, but it seems not at the end.
I thought about the drill damage, but I did a little experiment comparing coin alignement, and the 2 oddities seem not perfectly aligned, also reason why I thought it couldn't be drill.

But based on all answers I got, it seems either:
- drill attempt on both sides, explaining why it's not aligned
- someone on the other forum told "Drill mark for sure, it is not lined up perfect because the dies are not lined up as good as your overlay"
Thank you again for your precious answers!