Exactly, coming from experience in both the media and law enforcement... agencies do lie and omit pertinent information given to the media.
News departments are overworked, getting smaller, and even disappearing in some places. Facts are not checked and questions aren't asked as much as they used to. Media budgets are also smaller and less public records are requested. A television station I've worked with in my area, copies and pastes press releases into the script/website.
Anything said by a PIO is taken as the truth. In all of the larger agencies in my market, the PIO is a completely separate civilian position and 80% of the time, they are not on scene and send releases from their office or home. Most of the time, information gets reported to the PIO from the on-scene units, who in turn, parrots the information to the media (leaving out facts that might cause negative light of the department). If you are lucky enough to get a sound bite from a uniformed shift commander... your usual response to a question is "those details will be released at a later time pending further investigation."
Media dealing with encrypted agencies are almost completely at mercy to the PIO. Public records requests are very time consuming and at times, very expensive. I requested a personnel file of an officer and his E-mails for a week and the fee was over $200. Frankly, I don't think the gatekeeper of the information given to the media should be a person who's employed with the department. It's almost a conflict of interest, and more so when the media can't easily check the facts.
Even the best PIO's will never be able to provide timely and impartial information like a scanner can.