And sadly, let us stress to you that you may not ever hear the complete story of what they did or did not do to this employee as discipline.
My sympathies, I have worked in places where people who were reported or disciplined immediately brought down a complete investigation of the whole work area/department etc. They made tons of false allegations, pointed out the wrongdoings of others to both make themselves sound justified and to retaliate, not illegally. And then upper management feels obligated to check and follow through with all sorts of attention.
So as a supervisor, I'd always be prepared, if I were you, to be examined to the max and be asked all sorts of things by the people who were investigating your complaint against this person. Be blameless. (example, if other people in the work area are complaining about the one guy who's always late, or the one person who spends hours in the bathroom, be prepared, and tell everyone else in the work group it will happen, that after he's been approached, the problem person will say everyone comes in late, or everyone spends too long in the john. )