diff --git a/components/download/internal/common/download_item_impl.cc b/components/download/internal/common/download_item_impl.cc
index 2c2d4e8f098ff..b702b9e78a58c 100644
--- a/components/download/internal/common/download_item_impl.cc
+++ b/components/download/internal/common/download_item_impl.cc
@@ -37,6 +37,7 @@
 #include "base/logging.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/observer_list.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/to_string.h"
@@ -1454,6 +1455,11 @@ void DownloadItemImpl::OnAllDataSaved(
   hash_state_.reset();  // No need to retain hash_state_ since we are done with
                         // the download and don't expect to receive any more
                         // data.
+  // POC INSTRUMENTATION: emit the final hash so it can be compared against
+  // the actual sha256sum of the file on disk.
+  LOG(ERROR) << "POC-HASH-FINAL url=" << GetURL().spec()
+             << " bytes=" << total_bytes
+             << " GetHash()=" << base::HexEncode(destination_info_.hash);
 
   if (received_bytes_at_length_mismatch_ > 0) {
     if (total_bytes > received_bytes_at_length_mismatch_) {
@@ -2618,6 +2624,9 @@ void DownloadItemImpl::ResumeInterruptedDownload(
     } else {
       // There is not enough data for validation, simply overwrites the
       // existing data from the beginning.
+      LOG(ERROR) << "POC-CLAMP-OFFSET-ZERO received_bytes="
+                 << GetReceivedBytes()
+                 << " (stale hash_state already moved into params at :2604)";
       download_params->set_offset(0);
     }
   }