Moving a transition to the root level causes runtime error

[Phrogz]

1. Edit the text of the state chart to move a <transition /> out of a state at the root to be a child of <scxml>.

EXPECTED: SCXML parse errors cause the diagram to not change, or not show at all.
ACTUAL: Runtime error.

[Phrogz]

Note that it is invalid for SCXML to have a <transition> in the root. Who should catch this?