[BUG] negative duration and no endedAt timestamp in fileResults in egress_ended webhook

[mallison]

Describe the bug

A few times we've received an egress_ended webhook with a negative duration and no endedAt timestamp in fileResults. The status is EGRESS_COMPLETE.

Egress Version
Livekit cloud.

Egress Request
I don't have this.

Additional context
Webhook payload:

{
  "egressInfo": {
    "status": "EGRESS_COMPLETE",
    "endedAt": "1731668993605577585",
    "fileResults": [
      {
        "duration": "-1731660518186023947",
        "startedAt": "1731660518186023947",
        "size": "61941096",
        "location": "{storage}/4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe.webm",
        "filename": "4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe.webm"
      }
    ],
    "track": {
      "roomName": "4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe",
      "trackId": "TR_VSigWNEGdB4pmd",
      "file": {
        "gcp": {
          "credentials": "{credentials}",
          "bucket": "livekit-production"
        },
        "filepath": "4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe.mp4"
      }
    },
    "egressId": "EG_gyrUCPGmCQKw",
    "roomName": "4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe",
    "details": "end reason: source closed",
    "file": {
      "duration": "-1731660518186023947",
      "startedAt": "1731660518186023947",
      "size": "61941096",
      "location": "{storage}/4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe.webm",
      "filename": "4aa5307b-d1e4-4e9b-a664-dff8ce30d9fe.webm"
    },
    "updatedAt": "1731668993605577585",
    "startedAt": "1731660517131739111",
    "roomId": "RM_RLtuuhHswv6d"
  },
  "event": "egress_ended",
  "createdAt": "1731668994",
  "id": "EV_74j7SUwkJPwe"
}

Logs
None