Brief Description: During a team fight swiftblade ulted a Plollywag Priest. After 2 hits from the ult polly manages to use Storm Spirit. In doing this swiftblade's ult(with staff of the master) stops outright while there are many other targets in the surrounding area.
How to Replicate: Spam stormspirit on yourself as swiftblade ults you.
Match ID& In-Game Timestamps: Match I.D 29766993 Time: 48:13
Are you sure there were more (valid) targets in the AoE check of the affector? Off the top of my head, Swiftblade's ult's affector radius is ~400-450 and that AoE isn't as large as you might think.
I can't watch the replay now but will do so tomorrow (or tonight if I have time)