If you are still watching this thread...
The dipstick in my M103 engine does NOT protrude from the end of the tube when fully inserted. If yours is the same (and I would expect they all are), then if the dipstick is inserted quickly and pulled right back out, the pressure developed by the air and dipstick may force some oil back out of the tube. I would not expect much, but enough maybe to give you a lower reading. It is advisable to leave the dipstick in the oil for several seconds to allow the oil level to come up the same as the pan before removing.
'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)