While the Marshall lynches are not supposed to show roles until the end of the day, hovering the mouse over the graveyard reveals the roles of those who have been lynched by the marshall already that day, even if you're still in the process of lynching more.
Attached is a picture of this behavior happening while lynching a second marshall target on the same day (day 2).
This isn't a huge bug, I admit, because it doesn't bring anyone lynched back, but it goes against one of the core marshall drawbacks of not knowing who you've lynched until the day is over.
I've also found a game where this behavior is demonstrated. (This is not the same game from which the screenshot is taken.) You can find the dragon head's role as soon as he's lynched by the marshall(who was me) at about 13 minutes, by scrolling over the graveyard as any player.