"Repeated voting is prohibited"

Situation:
I read the tape, according to the title and the first paragraph I see what is interesting - I open it for reading in its entirety, in a separate tab. Having read a fragment of an article in a feed, I see that I like it. Vote in the plus.

After a while, I come back to the article, I read it entirely, and I’m semi-reflectively voting again. They write to me that a second vote is prohibited. But how many votes - do not show. I remember that I have already voted.

I think it is quite reasonable after the fact of determining the attempt to re-vote, immediately show the results of the vote.