Okay works now:
For others who are looking for this--
0403-057 Syntax error at line nn : `<' is not matched.

This is returned when using <<EOF, << EOF, <<-EOF, <<! etc. and all of the
permutations of syntax that preceed/follow.

If you are also finding this is a problem, I have managed to get around this by
wrapping the sql in a process to returning a value e.g.

ORA_RC=`$ORACLE_HOME/bin/sqlplus /nolog <<EOF
connect /as sysdba
................
EOF`