What happens is that the first evaluation is on $1-, not on the contents of $1-. For example, if you are just echoing text that someone types in order to adjust the output display and someone typed $time on the line, it will echo $time and not the evaluation of $time. That's because you are evaluating $1- and not the contents of it.
Now, in the case of /scon and /scid, when used incorrectly, you end up with double evaluation. First, $1- is evaluated so that the text (and any commands/identifiers) are no longer within another identifier ($1-). Then, a second evaluation happens. Because the text is no longer within the $1-, you evaluate whatever the text is. This means you'd evaluate things like $ip or $time.
