(CNN) -- Ellen DeGeneres, #Busted.
The Academy Award host broke Twitter with her Oscar-night group selfie using a mobile phone built by Samsung, a major sponsor of Hollywood's big night. It generated a record 2.7 million retweets -- a coup for her, the Oscars telecast and the Korean electronics maker.
But some sharp-eyed observers noticed something a bit different when viewing the talk-show host's backstage tweets. Several of them, such as a photo of DeGeneres with actor Channing Tatum, were sent not from a Samsung Galaxy handset but a rival iPhone.
The source of the photos and tweets can't be seen on DeGeneres' Twitter page, but is visible when they're viewed on another platform such as TweetDeck.
Samsung did not immediately respond to a request for comment from CNN. Several other photos DeGeneres posted were sent using an Android device, most likely the Samsung phone she used to pose with Bradley Cooper, Meryl Streep, Brad Pitt and a handful of other A-list stars.
A similar faux pas occurred in 2012, when after weeks of talking up Microsoft's Surface tablet, talk-show queen Oprah Winfrey sent a Twitter message touting the product to her 14.8 million followers. However, Winfrey -- or whoever managed her Twitter account -- sent the tweet from an iPad.
Some bloggers came to her defense, noting that no official Twitter app existed for the Surface's operating system at the time.
And singer Alicia Keys claimed she was hacked after she was caught tweeting from an iPhone last year while serving as a "creative director" for BlackBerry.
CNN's Doug Gross contributed to this report.