during an audit, can IRS look at attornies escrow account?

I would expect the IRS could.  It would be auditing revenues received
by the attorney.  Since the attorney controls payments to and from
escrow accounts, he could conceal receipt of funds  - a check -  by
depositing to an escrow account instead of to his own account.  Misuse
of escrow accounts is not unknown.
After year-end, having avoided recognition of income in the year being
audited, he could have the amount transferred to another account.  The
persons for whom escrow accounts are opened  (e.g., real estate
transactions)  have little reason to ask for account statements since
their transactions on an escrow account are simple  - in and out, and
the deal is satisfactorily settled.