I am not an SE authority but I see the workings of the sites since some years.
You, as a mod, can't work as an ordinary user. If you close or reopen, it will be closed or reopened on the spot. You can't vote as an ordinary user.
Contrary the majority of the websites, the SE allows us to have secondary user accounts, while we follow some requirements (not vote to eachother and so on). You could vote as ordinary user with them. Although this leniency might be more strict in the case of the mods.
Beware also, mods have to stand against many critics. If you closed a question, or reopened a question, it is your responsibility from that point. If the community does it by its votes, then you can point to the community, whose will you have to represent.
On these reasons, mods typically take only a little part in the reviews (although, in theory, they are allowed as they want to) and do anything only if they are very sure, this is what the community wants.
Typically, as a mod, the best strategy is if your workings are so invisible as it is only possible. This is the best defense mechanism. Speak little, do little, so there won't be anything to criticize in your work.
Although 3d printing is only a small site now, and you might think there isn't too much to do, it won't be surely so in the future. But be careful, particularly as your site grows.
As far I know, there is also an SO team (essentially, a closed SE site) only for the mods. I suggest to try to join it, if you can.
Such single-case mistake is surely not a problem, but the best if you do it silently. Digging the SEDE, I found many times as post closure/deletions/reopens/undeletes have been done, and then quickly reverted by a mod. So, it happens, but don't make a habit from it :-)