Can anyone explain why this happens?

[Zage]

Pac-Man's Dair normally does 10 point of damage if you connect all 4 hits (1-2-1-6). However if you only hit with the first hitbox and whiff the rest, the next time you use D-air the damage sequence changes to (2-1-2-6) giving you one extra point of damage. I've also had it give me 12 damage (2-2-2-6) randomly.

This was in training mode btw, so staleness and rage aren't a factor. I'm thinking other characters might have weird stuff like this happen with their multi hitting moves. What exactly is going on here?

 

[Espyo]

Remember that damage is kept as a float, not an integer. That means it has decimal places. Probably what happens is that the first hit connects, and you go from 0% to 1.8% (or something of the sort). The game shows only 1%, an integer. On the next attack, the first hit now causes something like 1.5% (repetition effect), which does add up to 3%. That's why you see 0% -> 1% -> 3% and think it changed from causing 1% to 2%. The same logic can explain the follow-up hits' damage.