Revert "tweak"

This reverts commit 229ac9a.

Author: FGasper

internal/verifier/clustertime.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/10gen/migration-verifier/internal/logger"
 	"github.com/10gen/migration-verifier/internal/retry"
+	"github.com/10gen/migration-verifier/internal/util"
 	"github.com/10gen/migration-verifier/mbson"
 	"github.com/pkg/errors"
 	"go.mongodb.org/mongo-driver/bson"
@@ -70,15 +71,22 @@ func fetchNewClusterTime(
 	ctx context.Context,
 	client *mongo.Client,
 ) (primitive.Timestamp, error) {
-	_, rawResponse, err := runAppendOplogNote(
+	cmd, rawResponse, err := runAppendOplogNote(
 		ctx,
 		client,
 		"expect StaleClusterTime error",
 	)
-	if err != nil {
+
+	// We expect an error here; if we didn't get one then something is
+	// amiss on the server.
+	if err == nil {
+		return primitive.Timestamp{}, errors.Errorf("server request unexpectedly succeeded: %v", cmd)
+	}
+
+	if !util.IsStaleClusterTimeError(err) {
 		return primitive.Timestamp{}, errors.Wrap(
 			err,
-			"failed to append note to oplog",
+			"unexpected error (expected StaleClusterTime) from request",
 		)
 	}