This has been a bug ever since 1.9 I am bringing villagers to a village and sometimes when I hit the boat, the villager gets hurt somehow, and it's making the villager raise trade prices because i accidentally hit them when i try to hit the boat.
MC-169637
attacking an entity with a sword can sometimes hurt other entities near it.
Resolved
Works As Intended
0
Sounds like Sweeping Attack effect which is normal https://minecraft.gamepedia.com/Sword#Sweep_attack
(Or possibly sweeping edge enchantment)