Bottom line: Profiles really tries quite hard to check the provenance of everything it sells. I think it's a matter of how squeaky the wheel is about a particular piece. The Grail helmet probably wasn't screamed about loud enough.
Phil, I must respectfully disagree with you, at least for the most recent sales.
The catalogs have been rife with errors that any iota of confirmation could have prevented.
Those movie cameras in Debbie's sale, being touted as silent studio classics, were made decades later and never saw the inside of a film studio in their lives. They were made for industrial uses as their date specific serial numbers attest. A quick call to the ASC Clubhouse in LA or to Sam Dodge was all that was needed. Instead, cameras worth a few thousand were sold for tens of thousands - a result still boasted on the Collectors Ransom blog.
One of several errors in the last sale attributed the Laurence Olivier suit to the 1940 Best Picture winner REBECCA, but had a clearly very modern Western Costume Company label that proved it was from the 1978 mini series THE BETSY. Here is an auction house that has handled probably more WCC pieces than any on Earth, and they cannot tell the difference in labels made four decades apart? Hence, a $400 suit sells for $4300.
If, they had published images of any labels for the costumes offered, I am sure I and others would have found many more errors, but for the first time, either in the printed catalog or online, are any shown. I know one advanced collector who asked more than once via email and online for image of just one label and they were never responded to. The Olivier client got an immdediate reply. This implies to me that there is a change in the wind and they are not willing for any peer review or anyone looking over their shoulder. The party ignored was asking about the John Wayne jacket, so they must have rightly been concerned they were going to ask me about it. The irony is, that client, a long time big dollar buyer, owns the pants and shirt that goes with the jacket offered and was sincere in their desire to authenticate it. It sold, again, on one bid at the low end.
You may attribute it to a weatlh of riches, too many sales in too short a period and much of the staff involved with the TV show - all sustainable arguments, to me. But, the fact is research has taken a back seat and many of the lots show it.
They used to do a much better job.