The BBC has determined that the broadcast of a racial slur during its coverage of this year’s Baftas went against its editorial standards.

During this year’s Baftas ceremony, Tourette’s campaigner John Davidson – attending the ceremony with the cast and crew of the movie I Swear – experienced a series of involuntary tics, resulting in him shouting a variety of slurs from the audience.

One of these, which saw him shouting the N-word while Sinners actors Michael B Jordan and Delroy Lindo were presenting on stage – was included in the BBC’s broadcast of the Baftas, which aired on a two-hour time delay.

Following the event, the BBC faced a wave of scrutiny – and a “large number of complaints” – due to the slur’s inclusion, with outgoing director-general Tim Davie “fast-tracking” an investigation into how it came to be broadcast.

On Wednesday, chief content officer Kate Phillips confirmed that the BBC’s executive complaints unit (ECU) had “found this should not have made it to air and it was a clear breach of our editorial standards”.

A post on the ECU’s website explained: “The inclusion of the n-word in the broadcast (which was also streamed live on iPlayer) was highly offensive, had no editorial justification and represented a breach of the BBC’s editorial standards, but that the breach was unintentional.

“The members of the production team who were monitoring the event in the outside broadcast vehicle all say they did not hear or recognise the n-word when it occurred at about 14 minutes and 45 seconds into the broadcast (while Delroy Lindo and Michael B Jordan were introducing the first award). The ECU accepted their account, for two reasons.

“Firstly, the use of the n-word in that instance was extremely indistinct, to the point where it might well not have been recognised by the production team. Secondly, there was another occurrence of the n-word about 10 minutes later, which was recognised by the production team and immediately edited out in accordance with the protocols on offensive language which were in place.”

The post continued: “There is no reason to conclude they would have applied the protocols in one case while deliberately ignoring them in the other. The ECU noted, however, that the BBC received one complaint from a viewer about the use of the n-word in the segment of the programme concerned while the programme was still on air and another very shortly after it ended.

“While this tends to support the view that the word was almost unintelligible (because we would expect a use of the word which had been clear to viewers in general to have caused a large number of complaints during the broadcast and immediately afterwards), it also means that we cannot say it was entirely so.”

As for the inclusion of the slur on the Baftas broadcast later uploaded to the BBC iPlayer catch-up service, the ECU said this was also “a breach of the BBC’s editorial standards”.

“The production team became aware shortly after the transmission of the first award that the interjection while Delroy Lindo and Michael B Jordan were on stage consisted of the n-word,” they said, saying that the delay in taking it down was a “serious mistake”, pointing out that by this point it had become “widely discussed” on both online and in news media.

In their findings, the ECU said: “The fact that the unedited recording remained available for so long aggravated the offence caused by the inadvertent inclusion of the n-word in the broadcast.”

A day after the Baftas, Kate Phillips sent an internal memo to BBC employees which read: “The edit team removed another racial slur from the broadcast. This one was aired in error and we would never have knowingly allowed this to be broadcast. We take full responsibility for what happened.”

After Delroy Lindo expressed his disappointment at the way Bafta had handled the incident, a spokesperson for the organisation later issued a lengthy apology which also took “full responsibility” for what transpired.