The situation is clear. The Spanish ships failed to comply with the Brazilian searches, and were fired upon as such. It in not the fault of the Brazilian Admiral that the Spanish refused to provide a reasonable explanation of their intentions before disobeying a search policy they said they would submit to.
OOC: Mexico and Colombia are good choices, although Sweden is a bigger power at the moment. Tbh, the choice isn't particularly great at the moment, but there are some nice regional powers left.