I would still argue that it's not necessarily the case with every static instrument.
In a simple, unpressurized airplane, the official "static" pressure (normally taken from the carefully sited static port) will not differ greatly from the internal cabin pressure. There might be a difference between cabin pressure and static pressure due to differences between inflow and outflow (ventilation) but it will be minor.
However, in a pressurized airplane, the difference between the official static pressure and cabin pressure will be a lot. Fly at 30.000 feet with cabin pressure at 6000 feet is not uncommon for a commercial airliner, but even a modest turboprop can easily go to 15.000 feet with 6000 feet cabin pressure. Have you seen the shape, thickness and general design of the windows on these sort of machines?
I doubt whether the single-milimeter thickness glass on the VSI would be enough to contain this pressure differential, so I assume that there are pressure instruments on the market today that are designed to be installed in pressurized cockpits. These instruments would have two pressure housings: one to hold either the vacuum (ALT) or the pressure from the pitot tube (ASI) and the second one to contain the static pressure. Smashing the glass on these instruments will not work at all - it's the housing that contains the static pressure that you need to smash (and you need to depressurize your cockpit).
Problem is, you can't see from the outside what it looks like on the inside. A VSI designed for a pressurized cockpit will look exactly like one for a non-pressurized cockpit when installed in your panel. And with all the trading in second-hand instruments going on, who's to guarantee that you don't have the pressurized type in your non-pressurized cockpit?
Anybody who has experience in pressurization who can confirm this?