I have a workflow that uses a Hotkey to trigger "Browse in Alfred". I've done this instead of using the built-in support so I can restrict the hotkey to only occur in the Finder, as that's the only app I ever use this feature with and the hotkey I use conflicts with Xcode.
Anyway, I just discovered a problem today, which is that Alfred interprets the flag changed events for the modifiers used by the hotkey incorrectly. As near as I can tell, it's trying to detect a quick press-and-release of the shift or control modifiers to trigger the associated behavior (quicklook or showing the action panel; I have control enabled for this behavior, I don't remember if that's a default). The problem is my hotkey is ctrl-shift-\, and if the modifiers are still held down by the time Alfred shows the panel, and I release both modifiers at the same time, Alfred will trigger one of the two behaviors (quick look or showing action panel, whichever one corresponds to the modifier that got released second). I'm pretty sure what's going on is the flags changed event doesn't actually say which flags were added/removed, it just says what the current flags are, so when the first modifier is released Alfred interprets this as the addition of the second modifier, so when that gets released it triggers the action.
This is rather irritating because it means I need to be really quick about releasing the modifiers when I trigger the hotkey or else I get this weird behavior. Alfred could fix this by keeping track of modifiers as global state, instead of what it's apparently doing which is keeping track of them only when the action panel is open. Or if it doesn't want to track modifiers globally, it could at least track the modifiers involved in a hotkey to see when they go away. Or poll the system when the action panel opens to see what flags are currently active.