Most installers whom do this as a business in the automotive field and/or send out persons to do window installs - use a multi-filtered system - and do not use distilled water - to install window tinting - at least the one's we know - do not. As a homeowner doing it yourself - yes - you are advised to use distilled water as a DIY'er, plus use some johnson's baby soap in a spray bottle with the distilled water in order help with adhering the tinting and making it easy to move it into place. No slight was made at you, by any means.
Didn't think you were slighting me, just weird you quoted me, and made a statement without me asking a question..lol
I have been on many installs with my good friend who owns his own tinting business (auto/residential), to lend a hand when I was bored, I am well aware of the process.
Plenty of shops use distilled water FWIW. It is more expensive though.