could have, Im no expert but will share my thoughts as to why i guessed what i did.
1st, a fish trapped on a hook and line is an akward thing. will make it easier to tear pieces off the trapped fish as the fish is being anchored into one direction.
i think if it was a 60lb dorado, only the head would be left. if may have been a few dorado but dorados dont take bites, they only tear off what can first wholly fit in their mouth which would either be the head/tail/midsection then tear that clean off. from top to bottom as opposed the damage seen which resemble more to bites.
a wolf may have bitten on, then twisted and tore a chunk off but then again, it wouldnt leave the clean looking bite marks, it would look torn off. and dont think the wolf would have struck several times this way. my wolf and ones i seen feeding on toutube usually strike, hold, and if needed, shift head towards gut then swallow.
looks like a group effort to me.
piyara pygo piranhas get to 20inches but not sure if they live in armatus waters. there are other serra piranhas that get large as well, but like i suggested earlier, smaller caribe/rbp/macs shoaling P's can and will make marks that look lie a larger fish made. I know cos I've fed large chunks of meat, large fish (dead) to my pygo shoal and the damage looked a lot like that.
take a closer look at the photo, its multiple bite markes, not a single.