Although it would certainly be a surprise, it would run it for later. At that point, the hope the player and perhaps the character is supposed to have is that they are either CGI or some very well done puppets.
Though there is the fact that this isn't entirely like the UP, so such a change could be made - but maybe it should be that you are attacked by a few of them, but they don't ash upon death, rather just disappear(which might be possible, I can't say). If not, just have these few be immune to damage, and the damage they do is minimal(or none) - and to get rid of them, the PC has to find one or two spots where a machine is projecting the holograms for them.
Could even be a small conversation that plays upon leaving the mausoleum, which would have a NPC talking on a phone(perhaps obfuscated).
"Yeah, that fledgling fell for it. The guy who stole the tape should've just destroyed it, but no, he chooses to try selling it to that egotistical fuck in the jewelery store. Whatever - even if this puts that lick on our trail, it won't matter. Hell, let the fool get deep enough, and the boss might realize he needs a new throne, I don't know. But this isn't going to screw us up. Hell, if anything would, it would be those idiots who stole a few tapes from the mansion. Yeah, I'll see about getting those tapes back - but I'll take care of the fledgling first. Oh, the boss is dealing with the tapes already? Good, I hate being around those creepy things."