Did he steal files? Yes. He has no right to share these files without author permission.
Unless he has total control over these files - I sell different licenses for my code changes/modules. Buyer always knows, if it's just a copy of my code or if I made it 'just for your OTS' (often 5-10x price, so I WON'T sell it to other OTSes), so they can sell/share it.
Do I care? No. Anyone can share code I told them not to public and I can't do anything about it.
If there were any stolen Tibia files, Cipsoft would sue every single OTS (IDK, if you missed OTS and open-source server history in 2005-2015).
They - Cipsoft - know, they cannot. Even WoW (World of Warcraft) - with 100x more players - failed in courts in Europe (after gaining 100kk $ from private WoW server in USA; that moved hosting to EU and won in court vs WoW): IF you post your 'game client' for free (freeware), you cannot sue 'owner' (OTS owner) for 'users' (players), which are using it with 'custom server' (different server setup ex. OTS - IPChanger).
It's 15-20 years since WoW court win in EU, but I would like to notice
@Codinablack @Tofame that OTSes in 2005-2010 years did not use
Tibia.dat (
BlackTek-Server/data/items/assets.dat at master · Black-Tek/BlackTek-Server (https://github.com/Black-Tek/BlackTek-Server/blob/master/data/items/assets.dat) ) - they used
items.otb -, not only because of 'random item ID changes on RL tibia', but also to DO NOT USE any RL Tibia Client files, that are copyright protected.
If BTS server with copy of 10.98
Tibia.dat get popular, Cipsoft can easily sue you for using their files