I get vague dip stick readings on my Spider 2.2 JTS. I think it's because of the curve of the dip stick tube. I suspect that the end of the dip stick has a tendency to scrape oil off of the walls of the tube and, in the process, it distorts the reading. If you think about it, that could certainly be the reason for one side showing way over MAX while the other side shows half full, for example. I'd go with the half full reading.
My normal technique on other cars has been to check oil after re-fueling by removing the stick, wiping it off, and then taking a reading. With most cars, this works fine. But with my Alfa I have recently started taking a reading on a cold engine before I leave my garage by quickly removing the dip stick and trying to get a good reading on the first look. The theory being that the oil has had a long time to drain out of the dip stick tube. Even then, taking subsequent "confirmation" readings leads to a certain amount of mystery, especially after I suspected a mechanic of over filling the sump.
You'd think that checking the oil would be a simple, straight forward procedure. But I'll have to say, my Alfa kind of irritates me with the way the dip stick seems to work. I do NOT completely trust the instrument panel oil level indicator.