I had seen that reported on before but it is great to have confirmation from someone who was actually there. Denny's reference to Quad 57s is also spot on - utterly transparent but you would fry them if used as studio monitors.
In a similar vein, back in the 80s, I brought my LS 3/5a's to a recording studio because I wasn't happy with the frequency balance of the then ubiquitous Yamaha NS 10s. The first bass note played nearly blew the Kef B110s in the 3/5a's. That was when I realised that what works in the listening room doesn't necessarily cut it in the control room.