In practice, the closing of books doesn't imply that the balances in the accounts are all debited/credited to the Profit and Loss Account/Balance Sheet. This is only the knowledge given in textbook. We seldom put entries in the Profit and Loss Account except prior year adjustments etc. and is normally not going to be used for accounts adjustments so called after closing the books.
There may be a wrong conception about Profit and Loss Account. Profit and Loss account may means the account itself in the ledger or it can be a statement showing the Income/Expenses and thus Profit/Loss for the period/Year which we now usually call it Income Statement to differentiate the interpretation.
The boss's personal expense should therefore be debited to Drawings Account (Current Account) and credited to Sundry Expenses Account. The ending balances in each account will then be accuractly recorded in the ledger. It is only a matter of redrafting the Profit and Loss Account (Income Statement). Remember, It is not a normal practice to debit the profit and loss account direct for normal account adjustments.