And inquiry, I think you may have just trusted a bit too much here. If this was someone who doesn't know Porsches specifically, I wouldn't figure this to be good advice. Flashing or solid red lights tend to set off alarms and wave flags in anyone's mind, and clearly you had your doubts here. You should have erred on the side of caution knowing that these cars have numerous failure points, some of which can have rather catastrophic results.
I don't mean for that to sound harsh and bust your balls, so don't take it personally. It's just a rather hard lesson to learn. I hope you're able to get this sorted out between this shop where your car currently is and maybe an engine from Jake Raby, and without breaking that bank too heavily.
Then, in the future, get the car on a flatbed when it starts yelling at you.