A small shop bug with full build (not game breaking)

I was just playing some LoL I had fullbuild and 5k gold just because it was boring to wait respawn timer I decided to spam buying elixir of wrath the bar that shows your gold on the shop screen started going down but the one in your hotbar didn't then I reopened shop and I had 5 k gold again Im not sure if you can do something unfair with it unless you count resetting your elixir over and over again, but just in case probably should check that you cant replicate it with something else to make it game breaking.