E280 - oil change, leak... and fuel filter p/n


So I have a 1994 Mercedes-Benz E280 W124 sedan since 1 february. I have taken it into my local shop for an oil change (next time I'm gonna do this myself).
So they put BP5000 on the quote, I guess it's this but not sure, will ask tonight:
https://www.bplubricants.com/en/prod...sco-5000-5w-40
Now what was also on the quote was the amount of 8 liters. He also mentioned it he said "wow yeah it takes 8 liters haha". At the time he said this, in my head, I was like ehhhh isn't the normal spec 7.5? And shouldn't it even be below 7 liters because of the pressure and causing of leaks? I didn't say anything

So guess what... after a few days I am getting oil puddles under the car. It's gotten worse over time and I have phoned the shop he said come bring the car at the end of the day I'll put it on the bridge and have a look it's probably a leaking carter seal.
So... if this IS the case what would you guys do. Tell him it's his fault because the amount should have been between 7 and 7.5 liters instead of 8?
Question 2:
Does anyone know the product number for the fuel filter in my car? M104 2.8 liter 1994. From a local site I got these two but I'm not 100% sure if they are correct or which one is better, Bosch or MANN.
Bosch: 0 450 905 203
MANN: WK 845



