I also tested your 'Hyper-Fishes' in v4.0 and it send out the same code but, in v3.0 it works like how mine does.
var hypeDocument = $("#obj5114 iframe").contentWindow.HYPE.documents["Testimonials"];
hypeDocument.startTimelineNamed('Main Timeline', hypeDocument.kDirectionForward);
Error message says:
Could you please help with this?