My question involves criminal law for the state of: New York

I was caught shoplifting in Apple store in New york City.
The value of merchandise being more than $100, I was arrested and taken to the precinct and booked. The court notice mentioned the charge as Larceny but also mentioned ACD - adjournment in contemplation of dismissal. And my case dismisses today.
I was told by the lawyer there that ACD will disappear when the case be sealed, as something that never happened.

The thing is: I am from Brazil, I have a legal tourist VISA and everything. I go to NYC every year to spend my college vacation. My case is going to dismiss today. So, the question is: -- Will I have problem to go back to NY again after my case is dismissed? Will I have a problem with the immigration?
I'm asking that because I was arrested and fingerprinted in the police station. I don't want to be deported on my vacation. By the way, I'm going to NY next december.

Look what my lawyer said to me:

"Your case is going to be dismissed. There is nothing either of us need to do. Once it is dismissed and sealed, you're free to travel back to the US as you please."

I don't know if I believe 100% in that. What do you think?

Thank you.