Jarvan Flag Bug [Gameplay]

Played a bot game with a Jarvan, and a glitch occurred with his flag. He threw out his e, then followed up immediately with his q, but his flag reappeared behind him. Jarvan was killed mid dash, so the duration was very short. However, he appeared to dash in the opposite direction of the flag (forward) even though it was apparently cast behind him. I'm not sure how to recreate this bug, but my guess would be to just e q immediately, or e q and then die mid dash.