The information might not be admissible to implicate someone, but it should still count as probable cause (IANAL). So they could legally use it to then search whoever may be implicated, and any evidence from that should be admissible.

There's no claim that they violated any rights searching the phone (which after all belonged to them), but that the process may be unreliable. That means it's still enough for probable cause, or that seems plausible to me. I don't know whether this is right.

Edit: I did some searching, and this seems to be correct. https://en.wikipedia.org/wiki/Taint_(legal)

>The most common of such usage is with reference to evidence, testimony, identification by witnesses, or confessions that have been obtained by law enforcement illegally.

If it's obtained legally, it doesn't count as tainted. http://legal-dictionary.thefreedictionary.com/tainted+eviden... has the same illegal language.