There seems to be a lot of accidental flag as out of date clicks in a AUR package page while trying to vote for a package. I also had such an incident. This can easily be avoided by having a confirmation box asking before flagging out of date.

For doing this just add the attribute onsubmit to the HTTP form for flagging out of date.

onsubmit="return confirm('Are you sure you want to flag this package as out of date?');"

The final HTML snippet would be

<form action="/pkgbase/package-name/flag/" method="post" onsubmit="return confirm('Are you sure you want to flag this package as out of date?');">
<input type="hidden" name="token" value="e858a7c013faac47817182cc9829f11c">
<input type="submit" class="button text-button" name="do_Flag" value="Flag package out-of-date">
</form>

Thanks.