If Dillon hits a playmate, remove him from the group. Put him in a time out and discuss his actions with him. Do not allow him to play with others for a few days. Then do so, but make it understood that Dillon is playing on a trial basis. Make sure he knows that violent behavior towards others will not be accepted.
Children are naturally curious and vivacious.
Child proof the environment, until Dillon is old enough to understand the word fragile. If Dillon acts up in a restaurant, get doggy bags and remove him from the situation. Don't spoil the evening for others. Let Dillon know that he won't be dining out with you again, until he has proven he can behave in public. And for goodness sake, if he's only a year or two old, skip the five star restaurants and take him to a child friendly environment.