Trust that if a lawyer sends a correspondence to the IRS it is very likely reviewed by a lawyer standard operating procedure. It’s virtually inconceivable that any IRS agents are corresponding in any depth with groups represented by lawyers without the involvement of IRS lawyers -else they might easily and unwittingly compromise the IRS’s position.
Sadly, many of the groups weren’t represented by lawyers and devulged data they weren’t required too, but still many were represented by lawyers. Which ultimately begs the question, didn’t the IRS Lawyers recognize there are an awful lot of conservatives being scrutinized? => Speaks to the culture of the agency.
The gub'mnt is it's own lawyer ~ and the expertise in these exacting procedures is usually going to be found in someone who hasn't cooked his brain at a lawschool.