for whatever reason, traders are excluded from the death / retreat rule. - when they are killed, they can come back... ( and be killed again ). - no idea why though. - of course its silly to come back when you were just killed - allthough, some transports can put up a good fight ( container transports for example ).
anyway - there are still two open questions about retreating...
what system does it apply to - when it comes to "not coming back" - the system that the chase started? - or the system where the chase ended.... - as some chases can last for several systems...
and.... when the chased one returns to the original system, cause the chaser left it - .... how must the chased one behave when the chaser returns to that system. - when someone has died, he must avoid this person, - as he is.... well, dead. - but when someone just retreated with his life, ship, equipment, cargo. - must he still leave aswell?