Considering his tune changed afterwards to some variation of "there are no files" and "Obama/Biden tampered with them so you can't trust anything in them anyway" he almost certainly was told something along the lines of them planting his name and involvement to levels he knows isn't true.
Which is likely why he keeps dancing around it, trying to figure out the best way to dodge the trap they left set for him in there.
Considering his tune changed afterwards to some variation of "there are no files" and "Obama/Biden tampered with them so you can't trust anything in them anyway" he almost certainly was told something along the lines of them planting his name and involvement to levels he knows isn't true.
Which is likely why he keeps dancing around it, trying to figure out the best way to dodge the trap they left set for him in there.
This is definitely the explanation that is in the right ballpark.