Site breached?

[Reese]

Yesterday, I got a Google alert that someone attempted to log in to the email address related to this account. I forgot I even had this account and the password is known to be compromised from other hacks (yeah password reuse is bad, my security standards 6 years ago weren't very high).

Anyway, the odd part is that the password was not linked to this email account in the previous breaches, and the email account was purely dedicated to this forum account. It's not used for anything else except registering for this forum.
The other odd part is, the password for the email address is the same used for this forum account as well.

I'm not saying this proves the forum was breached, but it's a little too odd to blame coincidence and lucky bruteforcing...
Anyone else got any Google alerts?