I don't know whether that is true or not but I came across the mention that Ledger wallets are assembled by Flextronics. This means that Ledger company doesn't have the facilities to produce hardware and rely on 3rd party which in turn may aper as the other potential "hidden" and weak section in the trust chain.
No, from my research ledgers devices are produced in China, maybe by this Flextronics, and than they are assembled in France.
I am not defending ledger in any way, but there is a difference between assembling and producing.