Incorrect number of votes after a Rollback

I tested this extension on XE 7.4.2 .

1. Create a new idea.
2. Vote Yes. With the same user, switch and vote No.
3. Make a rollback from last to previous version.
4. Check the votes in Ideas live table.

Actual result:

• After the rollback, there will be 2 votes: 1 for Yes and 1 for No, which is not correct (according to point 2 from description - the last vote of your user was ONLY No.).
• So, from what I see, both Yes + No votes had been kept after rollback.

Expected result:

• Even if I make a rollback, I expect to see the vote of my user for Yes, which was the previous action, not accumulated.