Inspectors like Gerald Walpin, who go after White Collar criminals, are VERY thorough. I'm sure he's quite accustomed to being challenged and bad-mouthed by the defrauders he's investigated, as well as from his bosses (in this case, the POTUS).
I think it's VERY safe to say he has archives upon archives. Additionally, the information he has NOT put forth would be quite interesting to be made public. Especially if it were to come up in front of a Congressional investigation panel -- which I COULD see the Dems doing to corral Obama from taking TOO much more of their power.