Reading on you lines, your code should look something like

if (condition){
print "DEBUG ($.) Call Length det='$detail' ($dh:$dm:$ds)\n" if $DEBUG
+; 
} 
else {
# TODO : Might want to issue an alert and solder on! safedie 
print "FATAL ($.) Encountered line of unknown length (",$#line + 1,")"
+;
}
[download]

So that means If the condition is true and if DEBUG mode is on then

print "DEBUG ($.) Call Length det='$detail' ($dh:$dm:$ds)\n" if $DEBUG
+;
[download]

would be executed.
Looking at your o/p, I guess the condition is failing.You should turn on-the DEBUG mode built in you script to get more details!