https://arstechnica.com/gadgets/2018/05/court-docs-show-apple-knew-about-the-bendiness-of-the-iphone-6-6-plus/

Newly released court documents reveal just how much Apple apparently knew about the iPhone 6's and 6 Plus' propensity to bend. A report by Motherboard shows parts of the documents that were made public by US District Court judge Lucy Koh (most of the documents remain sealed) and they say Apple's internal testing found that iPhone 6 and 6 Plus models were indeed bendier than previous iPhones.

"The iPhone 6 was 3.3 times more likely to bend than the iPhone 5s" and "the iPhone 6 Plus was 7.2 times more likely to bend than the iPhone 5s," the document states. Judge Koh wrote that "one of the major concerns Apple Identified prior to launching the iPhones was that they were 'likely to bend more easily when compared to previous generations.'"