HI There
After speaking with a colleague - we beleive that this might already be logged as an issue
Essentially if a camera roll on a users iPad/ iPhone device is extremely large. - Survey123 crashes if you have an image option and choose to select external
However if you take the photo from the application it works.
They mentioned it is also observed on AppStudio applications as well
If there is a Bug number that would be good - or otherwise I can log a case with Esri Technical Support.
You can downlaod this sample survey
http://arcg.is/2gYe9zI
John P