Disputing fails with no info

[TvrtkoM]

Not sure where to put this issue. It's probably related to chain code.

When trying to dispute outcome on web application, extrinsic fails. This is what happens on front-end:

    if (status.isInBlock) {
      events.forEach(async ({ event: { data, method } }) => {
        console.log('data', data.toHuman()[0]);
        console.log('method', method);
        if (method === "ExtrinsicFailed" && failCallback) {
          const { index, error } = data.toHuman()[0].Module;

Logging data.toHuman()[0] gives {Other: null}, there's no Module member and we get Cannot read property 'index' of undefined runtime exception.