I was there and these are completely snobbish lies. NO actor fluffed their lines (ever considered that this might have been deliberate so it looked real & extempore?) there was a gap in the music because....there was a gap in the score. No glitches and no restarts. The Aldwych is one of the most comfortable theatres in the West End so I presume you went for the cheap seats. During the curtain call the lighting DESIGNER did NOT leave the cast in the dark. I have no idea why you would publish such obvious lies.
This show fills massive 1,000 + seat venues across the UK & Ireland. Let working class people have an enjoyable night out!