Ok, i did read that in the first place. Only talks about Rollbacks, nothing about crashing in the middle of the fight. Pro Wiki though is a little more specific and i at least would like to hear some sort of an answer please :)
"The boss rework was issued and is still ongoing to improve the boss NPC's in general. All reworked bosses are coded in Python and not in Xanascript anymore, which gives new opportunities. Reworked bosses can now have held items as well. One of the biggest benefits is, that the Python script sees when if the server crashed in order to not count a lose in case the player fought against the boss while the server crashed. In such a case, the player can simply re-fight the boss."
according to that i should be able to rechallenge them, which i simply cant :/
Best regards