It’s all likely enough to be considered an argument by the defence and that’s all that matters. The jury will decide whether it was likely enough to give doubt about whether she was killed by PR.
I’m not sure what you mean when you say she’s in survival mode to be honest. The argument id put to that is that she had managed to walk a fair distance away from her house (whilst falling and struggling admittedly) and also managed to fight back during the rape and scratch his face. If she was capable of those acts, then I’d suggest she was capable of becoming disorientated and walking into the park too.
As for the car/bus suggestion, again I think we have differing opinions on depression and suicide. I do not see suicide as an impulse decision of “I know, I’ll just jump in the road”. If that’s how you feel suicide goes, then that’s your opinion and you are fully entitled to that.
To reiterate again, I do not believe LS committed suicide. But I am putting across the point that is a perfectly plausible point of discussion for the defence and the jury.