Yes, seems like security was very lax. An attendee wrote the following on BBC site.
“All the roads had been closed around the Hilton for hours, blocked off by law enforcement. But the security at the venue itself wasn't particularly heavy.
The man on the door outside only took a cursory look at my ticket from what must have been six feet away.
We took the lift down to the ballroom, and an agent wanded me but wasn't particularly interested in the bleeps set off by the contents of my inside jacket pocket. They did not ask me to turn out my belongings.
In short, the security felt like a regular White House Correspondents Dinner - one without the sitting president in attendance”.