do people know if it is like a deal breaker for airliners when they are hiring pilots?
It didn't used to be but depends on the accident - FWIW there are several pilots at my current outfit that got jobs a while back having been involved in quite serious (military) flying accidents.
Even if you were the "sole" pilot
, if the accident was down to circumstances you couldn't forsee or control and then couldn't mitigate the consequences then I'd expect most to cut you some slack. In fact talking about the accident (but only if asked) and what you learned as a result can use up some of the interview time that would otherwise be used for awkward HR type questions.....
Do not lie to the airlines, but do not volunteer the information if you do not have to.
Have a copy of the Aviation Authority report into the accident available
That's very good advice.