Thrip damage can look very similar so it's not a positive diagnosis for PepMV without running tests.
Can you tell if the jagged lines are on the surface of the leaves only (thrips feeding) or are they chlorotic throughout the depth of the leaves? I can't really tell from the photos.
Also, when I have observed mosaic it has "almost" always been accompanied by distortion in the leaves and general puckering.
That's the problem with all of the viruses - there is always something less harmful that looks similar.
btw... if you have washed clothes, showered. and don't use any of your possibly infected tools, you should be OK working on your friends plants.
Please keep us posted,
Steve