Currently builds which are being cancelled by parent are being reported for example like:
Id Status Begin Date Duration Triggered By Cancelled By #Dependents [Number of builds using this build as dependencies] #Dependencies [Number of dependency builds used by this build]
1674853 Cancelled 2014-01-13 15:16:36 1 hour 34 minutes 39 seconds Scheduler Unknown 0 builds 0 builds

If User A is cancelling the parent, then I would expect his name as well on child level. And in case of timeout I would expect to have instead of 'Unknown' the user Scheduler being reported.
Unknown is not very straight forward and quite confusing from user perspective.