Well you can prevent such scenarios with this application. Child Lock app has the ability to lock you outgoing dialing with the simple click of a button. This can also be password protected by user. So not only does it requires passwords to activate the blocking but also for unblocking(so that no one can play around).
It stores the list of outgoing calls blocked with date time, so that you can relate whether it was an accidental call or someone is trying to misuse you phone.
App is also under Admin Protect i.e user will be asked for activating the same at the time of installation and cannot be uninstalled under regular methodology. It does contain a Admin Protect removal action button to allow users to use it before uninstalling if required.
The same can also be achieved under your smart phone, Settings==>Security==>Device Administrators
Feedback is appreciated as always !!