EastEnders 25, BBC1

So then, oodunit? Was it the newlywed Bradley, overwhelmed by an emotional two-hander with his wife Stacey? Or Hardman Phil, perhaps, cracking under the demands of having to chew scenery while simultaneously destroying it in Ian's flat?

No – in the end it was roguish Jack who butchered an innocent line of dialogue after about 10 minutes. In his defence, counsel should plead mitigating circumstances: a high-tempo three-way exchange during a heavily hyped broadcast of the BBC's flagship drama serial that drew 16.6 million viewers.

Poor Scott Maslen's verbal fumble was, of course, the moment we'd been waiting for: delicious proof that, no doubt about it, we were watching a live broadcast of EastEnders. Because, other than Maslen's mis-step, a slight wobble from Peggy and an iffy zoom, the casual viewer would have been hard pressed to distinguish EastEnders 25 from any other pre-recorded half-hour of angst and clattering aitches in Albert Square. It was a technical triumph.

The producers revealed their ambition early. A series of short scenes teed up the various players in the evening's main business – the revelation of the identity of Archie Mitchell's murderer – before a swaggering series of shots at Ricky and Bianca's entirely convincing wedding reception in the Queen Vic. A live-broadcast EastEnders may have been a cute way to hark back to the genre's seat-of-the-pants origins, but the first five minutes signalled that the producers were not in the mood to play it safe accordingly. And so it progressed, smoothly, almost flawlessly, until the episode's climax, a roof-top chase that ended with Bradley's death and the revelation that it was Stacey who had bumped off Mitchell on Christmas Day in the Queen Vic.

So fluent had the production been that I found myself taking up the invitation to switch immediately to BBC3 for an altogether different kind of live show, a follow-up on the set of the episode that had finished broadcasting on BBC1 only seconds before. The first person on the end of George Lamb's microphone was Charlie Clements, who plays Bradley, just up off the tarmac with fake blood on his hair (and a preoccupied gaze that said "I've just lost my job"). Unfortunately, the remainder of EastEnders Live: The Aftermath illustrated that we had segued from a live drama that had miraculously and thrillingly convinced us that it might have been pre-recorded to a live broadcast that, in its "here we are live in Albert Square!" inanity, may as well have been pre-recorded.

Given the production highwire that EastEnders 25 tottered along, it was asking too much of it to attempt anything more daring by way of actual drama. Peggy glowered. Phil went one better and exploded. Much of the episode passed by in varieties of the pout-and-shout ding dongs that seem to be the currency of soap dialogue. A couple of years ago a celebrated episode of EastEnders comprised a 30-minute monologue from Dot Branning. I don't catch the show often, but if the few episodes I watched recently are anything to go by, June Brown attracts the most polished writing. (A series of spin-offs from EastEnders called E20 and featuring some of the soap's peripheral younger characters has been a success; it's tempting to demand similar attentiveness to Dot, but perhaps it's for the best that she remains exactly where she is.) On Friday night she featured in a knowing scene with Ian Beale – the two of them are the soap's longest-serving characters. In the midst of the melodrama, the writers contrived to have them watching an old videotape that Ian claimed he had shot around the square a quarter of a century ago. A few old faces flashed by on Ian's telly, but he and Dot looked about as impressed as any of us who ended up watching the clips show EastEnders: the Greatest Cliffhangers a couple of nights previously. It was a nicely underplayed passage, the antithesis of a "douf douf" moment, and all the more satisfying for it.