If he is on summary probation, usually minor traffic infractions are excepted, meaning they are not a violation. However, if they have a probation officer, I'm guessing they are on formal probation. Then Mr. Kaman is correct he should have the details of his terms.
I agree that you should review the exact terms of probation. For misdemeanor summary probation, the term "Obey all laws" typically does not include an infraction like a traffic ticket. If it is formal probation, the best bet it is to review the terms.