What you have learned is that in order to mobile foreniscs one must have the phone in physical possession. But what happens if you have an legal situation and you want to collect specific artifacts from the mobile phone i.e. an iPhone such as texts or SMS messages? And having the phone shipped to you is not an option?
Please do research as there are several companies that offer software where an user can download an commercial software that will let you walk the use through in creating a forensically sound backup of the phone then ship the package to you. Please identify at least few companies.