You and many other people are looking at it the wrong way. You wouldnt have fixed the situation if the timer wasnt there, because if the entire more was designed around not having the timer, the initial conditions would be completely different.
Removing the timer breaks the difficulty scaling of the dungeons and opens up plenty of ways to abuse the system, hence it would require multiple other ways to ensure difficulty, so its very likely the same guy would have left the party once he would notice that ie. the rest of the team is nothing close to killing the roadblock boss (and you would inevitably have fights like that somewhere in some dungeons).