Pitot System Question?
 

Going through 'Ace the technical interview' book and came across an issue.

According to the book with regards to the ASI.

Static Port Block = No change in ASI in level flight, Over read in descent, Under read in a climb.

Pitot tube Block = Stuck ASI in level flight, Under read in descent, Over read in climb.

But, if a pitot tube is blocked that doesn't mean the drain hole is blocked. So the pitot tube would effectively become a static port with an even lower pressure due to the Venturi/suction effect of the drain hole on the pitot tube.

Thus it should be,
Pitot tube block = 0 indication in all stages of flight. because the pitot tube will always have a lower pressure than the static port unless at rest.

Is this right?