Half of me kind of hopes there was something else that happened behind the scenes that we didn't see, since the whole death was cut off.

Plus this is Geass. Anything is possible.

Though my guess is we'll find out in a later episode exactly what happened. I'm sure they thought we'd just connect Shirley & Rolo meeting up = Shirley's death since Rolo is extremely possessive yadda yadda yadda. But it could just be a plot twist. Like always.