As I reported here T184856#4426468, IABot sometimes leaves an unnecessary space before the closing </ref> tag. As far as I can judge, it is because there was a space between the cite and dead link template. IABot should delete every whitespace characters after <ref> and before </ref>tags.

The linked case:
<ref name="HereWeGoAgain">{{cite web |url=https://twitter.com/ddlovato/status/1957085257 |title=Demi Lovato First Single Announcement |publisher=Demi Lovato |accessdate=2009-05-29}} {{Dead link|date=November 2010|bot=H3llBot}}</ref>
->
<ref name="HereWeGoAgain">{{cite web |url=https://twitter.com/ddlovato/status/1957085257 |title=Demi Lovato First Single Announcement |publisher=Demi Lovato |accessdate=2009-05-29 |archiveurl=https://web.archive.org/web/20151208085451/https://twitter.com/ddlovato/status/1957085257 |archivedate=2015-12-08 }} </ref