OfCom's two-month consultation period on the issue closed on 25 July and, as far as I'm aware, they have yet to complete their report:
http://media.ofcom.org.uk/2013/05/17/improving-the-quality-of-live-tv-subtitles/
Live subtitling is done by computer software which inevitably struggles to cope with regional accents, poor diction and broadcasts where there is a high level of background noise. One proposal being considered by Ofcom and the broadcasters is that 'live' programs should actually have a few seconds delay built into them, so that human intervention can override obvious errors. (Some broadcasters already use similar delays, in certain programs, to ensure that unsuitable material doesn't go out. For example, Radio 4's 'Question Time' has a few seconds delay to ensure that militant protesters can't chant anything unsuitable on air). So the idea is certainly feasible.
Perhaps it might be better to wait to see what comes out of Ofcom's report before going any further?