Editor is actually pretty senior - certainly a big step up from producer. I know US network news organisations tend to have their chief anchor also being managing editors, and I guess this is the closest equivalent. All UK anchors work "for" an editor who is not on-screen. So while she wasn't CEO of ITN, she was in charge of what news went out on ITV. ITN also supplies the news for Channel 4 and Channel 5 in the UK, although those channels have their own editors and also have some separate correspondents.
And of course UK broadcast news outlets have to be non-partisan by law. In any case, I can't really think of anybody ever hurling those kind of accusations at ITV/ITN's news coverage.
Adam