Since the SSLVPN is run as an applet on the workstation, the Java Console on the workstation is where you would need to look.
You can also enable more debug in the Java Console, by setting a Directory Cookie for the user.
Adding the following code to the Profile login script the test user is using:
setDirectoryCookie ("SSLVPNDebug", "true")
will enable more SSLVPN debug in the Java Console.
set that directory cookie to false or delete the directory cookie on the users object when done.
** Since this will set it for any user logging into the system you may want to use a test profile or wrap the setDirectoryCookie with
if user "cn=joeusser,dc=company,dc=com" THEN
setDirectoryCookie("SSLVPNDebug", "true")
END