Hi, I'm Randy. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP.
yes, they can still recover data from an iPhone that has been erased.
when you delete information off your phone or undergo a factory reset, the data itself is not being deleted, it still remains in areas of the flash chip called solid state memory. Factory resets only destroy the paths to the data. This obviously allows forensic software users to re-establish their own pathways and retrieve the data.
A full removal of personal data is not possible using a device’s in-built factory reset or by re-flashing the operating system.
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