Change in itr form

Dear Sir / Madam,

One of my friend is in F.Y 16-17 working with one private orgnisation on honorisum so didnt get form 16A, His Accountant has filed his return ITR 4 under 44ADA and declare 50% of receipt as profit, later on in F.Y 17-18 he started his own office. 

Now my question is his 16-17 return filled under 44ADA so he has to continue to file return under 44ADA for next 4 years too, and he will not able to claim the business expenses too...

I am right, or whether he can file return ITR 3 and claim the business expenses by declaring profit more than 8%. 

if yes please tell how can he do so.

Thanks in advance.