dude, when you put the pump on the shock, air comes out of the shock and fills up the hose giving you a different reading than when you last pumped it
now 50 psi is quite a bit but unless you have a high quality pump, my guess is that shock is perfectly fine.Beside, is a 175 psi fair amount of pressure and even if you did have even the smallest of the leaks, it would go much lower than 125.
My experiance with air shocks is the pump (rock shox) will read 10psi lower than i pumped it up at the first time. also after a rebuild the shock will leak until its first use due to excess amounts of lube under the seals. untill that stuff is pushed around a little I think its possible for air to leak out. this could be the same for new shocks but I never noticed that.
the qa on cane creed db airs seems to be rather not solid ^^ a friend of mine got two.
one for his v10 and another for his enduro.
both had bushing play (even the first replacements sent to him by cc were not ay better) and the 2nd one looses all air within a day ^^
You wouldn't notice such a big difference in the pressure like some people say. On a piggyback which has a very small air chamber and a big percentage of the air goes into the pump to get a reading, yes. On a relatively high volume air spring chamber, no, maybe 5 psi at most.