You are right, they sucked it form the dipstick tube. When I saw that they
were not going to lift up the car, I ask them why and they told me "we´re
going to suck the oil from above, because ... etc". I took this as from the
oil cap. Sorry, my mistake, I was mad. I know it would be a "bit" hard to
get it out from there.
I already sent them to hell, but now I'm doubting, you say that this
practice is usual.
But then, I wonder why so much ugly garbage came out..., maybe as you
concluded, after all they were just "adding" some oil!... those thieves!
Anyway, a new oil change within few weeks and that´s all. It sounds good.