AttributeError: 'User' object has no attribute 'add_roles'
Sentry Issue: [BOT-1N6](https://sentry.io/organizations/python-discord/issues/2661278228/?referrer=github_integration)

```
AttributeError: 'User' object has no attribute 'add_roles'
(1 additional frame(s) were not displayed)
...
  File "bot/exts/help_channels/_cog.py", line 477, in on_message
    await self.claim_channel(message)
  File "bot/utils/lock.py", line 108, in wrapper
    except discord.Forbidden:
  File "bot/utils/lock.py", line 108, in wrapper
    except discord.Forbidden:
  File "bot/utils/lock.py", line 108, in wrapper
    except discord.Forbidden:
  File "bot/exts/help_channels/_cog.py", line 128, in claim_channel
    await self._handle_role_change(message.author, message.author.add_roles)

Unhandled exception in on_message.
```

This happened as the user was banned from the server in time time between sending a message to open the help channel, and this line of code being hit.
diff --git a/bot/exts/help_channels/_cog.py b/bot/exts/help_channels/_cog.py
index 498305b4..3c6cf7f2 100644
--- a/bot/exts/help_channels/_cog.py
+++ b/bot/exts/help_channels/_cog.py
@@ -125,14 +125,21 @@ class HelpChannels(commands.Cog):
         """
         log.info(f"Channel #{message.channel} was claimed by `{message.author.id}`.")
         await self.move_to_in_use(message.channel)
-        await self._handle_role_change(message.author, message.author.add_roles)
 
-        await _message.pin(message)
+        # Handle odd edge case of `message.author` not being a `discord.Member` (see bot#1839)
+        if not isinstance(message.author, discord.Member):
+            log.warning(
+                f"{message.author} ({message.author.id}) isn't a member. Not giving cooldown role or sending DM."
+            )
+        else:
+            await self._handle_role_change(message.author, message.author.add_roles)
 
-        try:
-            await _message.dm_on_open(message)
-        except Exception as e:
-            log.warning("Error occurred while sending DM:", exc_info=e)
+            try:
+                await _message.dm_on_open(message)
+            except Exception as e:
+                log.warning("Error occurred while sending DM:", exc_info=e)
+
+        await _message.pin(message)
 
         # Add user with channel for dormant check.
         await _caches.claimants.set(message.channel.id, message.author.id)
['bot/exts/help_channels/_cog.py']