As a former iPhone repair technician, I can confirm this is both true and false at the same time. There’s a speaker in the normal position for the ear as well, it all depends whether the user decided to put the phone into loudspeaker mode.
This comment coming from an Android user that’s just as guilty of this at times.
Even with a washer, the head of a straight bolt won’t hold very well in concrete when you go trying to tighten it, it’ll most likely start spinning and possibly even damage the concrete.