Line of Duty: is Ted Hastings really innocent?

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When you think about it, there are a fair few black marks against Ted's name that aren't explained away in the series finale. Could Ted still be the final 'H' AC-12 are looking for?

Why did Ted really visit Lee Banks in Blackthorn Prison?

This mystery was never fully resolved – and Detective Chief Superintendent Patricia Carmichael (Anna Maxwell-Martin) is still convinced Ted used the visit to blow John Corbett's (Stephen Graham) cover. Is she right? And if so, did he mean to cause Corbett's murder?

Watching footage of Lisa McQueen's (Rochenda Sandall) interview, Carmichael turns to DCC Wise (Elizabeth Rider) and reiterates her belief that the only reason Lee Banks knew there was a rat within the balaclava gang was Ted. But "without his testimony, you can't prove Hastings blew Corbett's cover," Wise reminds her, twisting the knife on Carmichael's own bent officer, PS Tina Tranter.

But if Hastings didn't tell him, then how else did Banks know the balaclava gang had a leak? Sure, there are other infamous residents at Blackthorn who could have tipped him off (that is, if he did actually inform the OCG – Lisa is an unreliable witness, remember). But it's a hell of a coincidence that the day Ted made that visit was the same day John was dispatched in grisly fashion.

It seems likely that Hastings did pass information about the "rat" to Lee Banks – but perhaps he didn't mean for Corbett to actually get killed. In his interview with Carmichael, when asked how the undercover cop would respond to having his cover blown, he suggests that Corbett would take refuge in a police station. It could have been part of a (failed) master plan to get Corbett back inside the fold and cooperating with AC-12's investigation.

The spelling of "definately"

One of Carmichael's strongest pieces of evidence against Hastings was the spelling mistake he made in his communications with the balaclava gang. Posing as 'H', he spelt the word "definitely" as "definately" – a mistake he shared with the real-life bent copper communicating with the balaclava gang via instant messenger.

During the interrogation, Ted's defence was laughably shaky – he argued that, in addition to his myriad AC-12 duties, he had studied the linguistic habits of this mysterious senior policeman and adopted them in his messages (instructions that, we should add, he wrote on the fly – much to the chagrin of cyber expert Amanda). At the time, it became another cog in the mounting evidence against him, but once Gill was exposed as bent, no one seemed to notice that this significant detail was never properly explained away.

It seems inconceivable that the spelling error was a conscious effort by Ted. So was his mistake a coincidence? Or a nagging indication that he could really have been the crooked copper conversing with Lisa and John?

What else was Ted doing on his laptop?

Carmichael was ruthless in her interrogation of Ted. She had a heap of evidence, including photos of the AC-12 boss getting rid of his laptop. The weight of her case even led the painfully private Ted to admit to using it to watch pornography. "It was private stuff. My wife has left me and... Jesus Christ. I really don't want to discuss it," he muttered.

But bundling his computer in bubble wrap and taking it to an electronic disposal shop seems an extreme move for someone who's done nothing more than watch a bit of porn. And remember, we've seen this laptop used for other purposes. Cast your mind back to episode two of the fifth series and you'll recall that shot of Ted's hotel room, when the camera panned back and we saw a line of text pop up on the screen. It looked suspiciously like the messages that 'H' used to communicate with the balaclava gang.

No porn on that screen, is there?

That extra £50k

Ted's behaviour was VERY fishy when Mark Moffat casually dropped him an envelope filled with £50 notes. In his police interview, Carmichael and her team referred to the £50,000 recovered from his hotel room, but Mark Moffat later admitted the advance he handed over was £100k. So, is half of that money still in Ted's possession? We saw him hovering near John Corbett's grave at the end of the episode, watching his widow Steph, with an envelope in hand. Was the extra money in it? And was he planning to give it to her?

If it is, his gift could well be motivated by guilt or pity. But handling an envelope stashed with cash is not the sort of behaviour we expect from an AC-12 officer, let alone Ted.

Why was Ted so anxious?

Remember Jane Cafferty, and her AC-12 interview where she identified Matthew "Dot" Cottan as the officer who recruited her? Remember when Kate and Steve asked her to single him out from a selection of photographs showing suspicious policemen? And remember when Kate added a final, mysterious photograph to the collection – an image we, the viewer, never saw? And then remember how anxious Ted looked as he watched the interview room, shooting worried glances in their direction from the confines of his glass-walled office?

Good. Because it was never made clear why Ted was quite so jumpy, was it? Sure, he didn't love it when Kate and Steve went off on their own missions without informing him – that might account for some of his discomfort – but that man was ANXIOUS.

Why, if he didn't have something significant to hide?

Some seriously reckless behaviour

During his interview with Carmichael, Ted claimed he went to extremes to track down 'H' because he didn't want AC-12 to fail in their mission. So dedicated is he to the cause, that he staked his life and career on that unauthorised undercover visit to the OCG's nightclub.

Do we believe him?

The Ted we got to know across the first four series was a man who stuck to the letter of the law – a stickler for process and authority. So it felt a little off when he went so off-book. And imagine if Miroslav hadn't accidentally left his phone on? Would our man have ever been tracked down? Would Ted have turned up in another body bag – or would he have had other means to ensure his safety?

He may have survived. But we can't help but wonder how series six will treat our Ted...