Yes, that is what the grammers tell me. There appear to be several not_so_standard ways of rendering expressions like οὐχ εὑρέθησαν. I looked at all the NT samples using the scriptorium to try and work out what was going on in the syntax. An imperfect method. The parsing is done by an auto_parser that you can download from the scriptorium.
RE: dropped negative particles
In my encroaching old age I have observed that the dyslexia that has plauged me since childhood has only increased and for some reason I am dropping negative particles. Perhaps there is some explanation for this but I couldn't find one. Since 2Peter had canonical problems the early manusript evidence is pretty thin. Could be we are looking at an early corruption related to "dropped negative particles" which I haven't found discussed in the NT TC literature. Doesn't mean it isn't there but I have looked several times without success.
I have an old friend who is a publisher and editor. I caught him dropping a negative particle. Five minutes ago I sent him an email in which I dropped the negative particle. It doesn't go away just because you are aware of it.