Starting a 4v5 when your teammate is split pushing is inting
and you will 100% get reported. it is not the teammate's fault you're retarded and can't count or listen to pings. Even having Baron doesn't mean you monkey push a lane and then dive their inhibitor turret. Baron is long enough that you have time to split push a little and then group, creating an even bigger advantage.
exception being when you're massively ahead and will easily win the 4v5.