Its not a matter of fake personality. The dude in that call wasn't 12. There also isn't any indication of a voice changer
i'm thinking of a few situations
either
1. it was someone else calling for storm surge
2. it was actually storm surge who called but the 12 year old was actually someone else who LOOKS like storm surge
i don't know, honestly. or it really is storm surge and maybe that was a really good voice changer, who knows.