It's virtually impossible to puncture a lung with a PICC because it is inserted in the arm -- most preferably the basilic vein not in the area above the clavivle close to the lung- However, on rad reads the Docs will still state there is no pneumo noted. I laugh each time I see it.
There is actually a seminar that is presented in Fl for this very thing by nurses-- I believe it's called the eclectic skin institute-- i was planning on attending a training a fwe years ago in Fl and that was where these nurses were from -