Reddit user MexieSMG discovered that, while extraordinarily rare, it is possible to tie on a Payload map in Overwatch.
Under most circumstances, it is highly unlikely for both teams to push the Payload the exact distance with the exact amount of points to enable a draw.
In a clip uploaded to YouTube, the red team pushes the payload to the last point on Eichenwald during Overtime. While the blue team is quick to intercept, the payload actually moves a little on its own while it is contested, adding to the red team's push distance. The red team suffers a team kill, the Overtime meter runs out, and bizarrely the blue team is unable to capture the payload. As you can see in the clip, the blue team is clearly on the payload while Overtime is in effect.
The game ends in a draw, even more bizarrely so because the red team had pushed 17.46 meters compared to the blue team's 17.45 meters. It is unknown if this is a bug, but nonetheless it must be frustrating for both teams.
Several reddit users on MexieSMG's thread and other threads addressing draws on dedicated escort maps, claimed to have experienced the same problem. Dorado is brought up in several anecdotes, implying that drawing on payload maps may not be as unusual as it seems.