Yes it can happen. Press Refresh (F2/F5 , depending on keysetup) and it will refresh it..
It can happens if the icon are fetched before the file copy is done, or if the file is used by another process.
icons are fetched in the background. When it detected a new file in the file system the file system refreshes and if new files then starts the background task to get the icons. Problem is if this happens to fast and the file copy is not complete yet. Then it will not find the icon since it is stored at the end in the .exe and it will not find a icon.
Also AntiVirus software always scan .exe file and this might also prevent the the icon from being fetch since the file is locked by AV.