If you send him a thumb drive with Proxies copied from the disc they can use XDCAM Browser or PDZ-1 (both free Sony apps at
http://www.sony.com/xdcam-downloads)to read the proxies. Copy the proxies using the camcorder (assuming it supports this, has to be 700/F800); this will create a virtual disc image that Browser or PDZ1 can open. Unfortunately neither of these apps can open standalone proxy files stored on something other than an XD disc image.