It seems some of the reactions in the viral glitter bomb video last week appeared to have been faked.

Former NASA engineer Mark Rober uploaded a video to YouTube on Monday that showed him pranking thieves who were stealing his packages. He designed a fake Apple HomePod package that blasted glitter and fart spray after the box was opened. Four phones inside the package recorded all the action.

The package was then placed outside of Rober’s house, as well as at other people’s homes. The revenge video garnered more than 42 million views.

Now, Rober has acknowledged that some of the reactions in his original video may have been staged. The dubious scenes took place when the packages were placed at other people’s homes, though he stood by the authenticity of those recorded at his own home.

“I was presented with information that caused me to doubt the veracity of 2 of the 5 reactions in the video,” Rober said in a statement posted on YouTube and Twitter on Thursday. “It appears (and I’ve since confirmed) in these two cases, the ‘thieves’ were actually acquaintances of the person helping me.”

Rober has since removed about a minute and a half of the original video to delete the apparently faked reactions.

Viewers began dissecting the original video soon after it was uploaded and noticed some inconsistencies, as reported by BuzzFeed. People on Reddit wrote that they found it odd no police were involved, and also noted that the thieves’ reactions were relatively calm after getting blasted with a cloud of glitter.

Rober didn’t respond to requests for comment.

“I’m really sorry about this,” he said in the statement on YouTube and Twitter. “Ultimately, I am responsible for the content that goes on my channel and I should have done more here.”