There's an Idea I recommend you vote up for the reporting for Macs:
Scan results displayed for SEP for Mac clients in SEPM's Reporting needs expansion
What you will probably want to look at is actually on the client machine: with the SEP client interface open, look under Tools then View History. That will show you Date, Location (you will have to hover your mouse over the file name to see the full path), Virus and Status. Unfortunately, the log can't be exported.
In 3+ years with working with AV for Macintosh I have never once encountered a machine that was actively infected. Java cache detections, W32.* detections, and macroviruses from old Word documents, yes, but not a true OSX infection.
What was detected was probably a PC file (or something related to a Windows-only threat), and I would bet it was picked up by Auto-Protect.
Hope this helps.
sandra