Not at all. Cold oil will cause higher pressure.
In the 78 450SEL I used to have, the oil pressure gauge would read 10-20 psi when I cranked the engine during a compression test.
You're probably familiar with full scale oil pressure gauges in other cars. MB uses about a third scale gauge. If it went to 10 or 100, depending on whether yours is a 1-2-3 bar or 10-20-30 psi gague, it would act as you'd expect and oil pressure gauge to act.