I looked for court cases, but I couldn’t find anything (maybe I didn’t search right or didn’t read right, though).
I used this URL to get access to the Judicial Yuan’s cases:
http://jirs.judicial.gov.tw/FJUD/FJUDQRY01M_1.aspx
I used that particular URL because it allowed me to use Google Translate in the Chrome browser (thanks to @olm for that information).
I chose the Pingtung District Court, and I put in a range from, I think, April (04) 1 (01) of last year (Republic of China year 106) to February (02) 8 (08) of this year (Republic of China year 107) and then changed the end date to February (02) 7 (07) (I know, both end dates are impossible, but I haven’t slept yet, or that’s my excuse).
I think I used the keywords inicio and inecio (supposedly one of those is the victim’s given name), and I think I also used the word prio (I guess his surname?), but I got no result for any of those. I tried 西班牙 on both criminal and civil. For criminal, I don’t remember getting anything, and for civil I got some lawsuit having to do with contracts, or fraud, or something like that, and the events in question in that case occurred before 2017. I tried 衝浪 (surfing? surf?), and I got, I think, a criminal case, but as far as I know, it didn’t directly involve something that happened at or around a time in which someone was surfing or fishing.
Somewhere in my searching I got a lawsuit involving a beating and a person from Spain, but the injuries seemed different, and I don’t think it had anything to do with surfing or fishing.
(Edited to add: I just now noticed that the hospital report reproduced in this thread gives the victim’s name as Ignacio and Ignaecio. I searched the civil and criminal cases in the Pingtung District Court with those two names, but I got no result.)
(Just as a side note, in case anyone ever uses that website: When I got cases, I had trouble using Google Translate to translate the text of the cases in the Chrome browser, until I clicked the link to print the text (located in the upper right area of the page; the Chinese characters are 友善列印). Then I could translate it in the Chrome browser.)