Unable to catch IllegalStateException in MLKit Document Scanner

Question

I'm building a Flutter plugin (mlkit_document_scanner). The purpose of the plugin is to provide a wrapper around the new MLKit Document Scanner. My problem is that I cannot observe an event in which the MLKit Document Scanner is exited without an image taken.

Here's how I'm launching scanner activity:

// Construct document scanner
val scanner = library.buildGmsDocumentScanner(
    maximumNumberOfPages = call.argument<Int>(ARGUMENT_NUMBER_OF_PAGES) ?: 1,
    galleryImportAllowed = call.argument<Boolean>(ARGUMENT_GALLERY_IMPORT_ALLOWED)
        ?: false,
    scannerMode = call.argument<Int>(ARGUMENT_SCANNER_MODE)?.let {
        val allowedScannerModes = listOf(
            GmsDocumentScannerOptions.SCANNER_MODE_FULL,
            GmsDocumentScannerOptions.SCANNER_MODE_BASE,
            GmsDocumentScannerOptions.SCANNER_MODE_BASE_WITH_FILTER
        )
        if (allowedScannerModes.contains(it)) it else GmsDocumentScannerOptions.SCANNER_MODE_FULL
    } ?: GmsDocumentScannerOptions.SCANNER_MODE_FULL,
    resultMode = DocumentScannerResultMode.values()[call.argument<Int>(
        ARGUMENT_RESULT_MODE
    ) ?: 2],
)

// Launch document scanner activity, and collect failure if it occurs
activity?.let {
    scanner
        .getStartScanIntent(it)
        .addOnSuccessListener { intentSender ->
            Log.d(LOGGING_TAG, "Launching document scanner")
            documentScannerLauncher?.launch(
                IntentSenderRequest.Builder(intentSender).build()
            )
        }
        .addOnFailureListener { exception ->
            Log.e(LOGGING_TAG, "MLKit threw exception:\n" + exception.message)
            result.error(
                ERROR_CODE_START_SCAN_INTENT_FAILURE,
                ERROR_MESSAGE_START_SCAN_INTENT_FAILURE,
                exception
            )
        }
}

I have the following code for collecting results from the launched activity.

fun handleActivityResult(
    data: Intent?,
    eventSinkJPEG: EventChannel.EventSink?,
    eventSinkPDF: EventChannel.EventSink?
) {
    val documentScanningResult = GmsDocumentScanningResult.fromActivityResultIntent(data)
    if (documentScanningResult == null) {
        Log.d(LOGGING_TAG, "NOTHING CAME BACK FROM THE SCAN!!!")
        return
    }

    documentScanningResult.also { result ->
        result.pages.let {
            if (it.isNullOrEmpty()) {
                Log.d(LOGGING_TAG, "null response (result.pages)")
                eventSinkJPEG?.success(null)
            } else {
                Log.d(LOGGING_TAG, "JPEG pages count ${it.size}")
                eventSinkJPEG?.success(it.map { page ->
                    page.imageUri.toFile().readBytes()
                })
            }


        }
        result.pdf.let {
            if (it != null && it.pageCount > 0) {
                Log.d(LOGGING_TAG, "PDF pages count ${it.pageCount}")
                eventSinkPDF?.success(it.uri.toFile().readBytes())
            } else {
                Log.d(LOGGING_TAG, "null response (result.pdf)")
                eventSinkPDF?.success(null)
            }
        }
    }
}

The exception that is thrown is the following:

E/GmsDocScanDelAct( 5777): Failed to handle scanning result
E/GmsDocScanDelAct( 5777): java.lang.IllegalStateException: Failed to handle result
E/GmsDocScanDelAct( 5777):      at com.google.mlkit.vision.documentscanner.internal.zzg.run(com.google.android.gms:play-services-mlkit-document-scanner@@16.0.0-beta1:12)
E/GmsDocScanDelAct( 5777):      at android.os.Handler.handleCallback(Handler.java:938)
E/GmsDocScanDelAct( 5777):      at android.os.Handler.dispatchMessage(Handler.java:99)
E/GmsDocScanDelAct( 5777):      at android.os.Looper.loopOnce(Looper.java:210)
E/GmsDocScanDelAct( 5777):      at android.os.Looper.loop(Looper.java:299)
E/GmsDocScanDelAct( 5777):      at android.os.HandlerThread.run(HandlerThread.java:67)

No logs indicate that activity was destroyed/no results were returned. I wonder if there's any other way to reliably predict this IllegalStateException.