Siddle told Sky Sports News: "It just happens. It's the umpire's decision and you take it and keep going on. That's what we did. There wasn't a big deal made about it. We got on with it and kept working to get the wicket.
"I'm a player, I'm not the one who writes the laws. Obviously people are going to be frustrated but it's hard out there for players and umpires. It's a long tough day for people out there.
"We have to deal with it and spectators have to understand things like that happen. It's a long day and tough work for everyone involved. We can't go blaming anyone."
Broad was 47 not out as England reached 326-6 at the close of play.