I found a bug in Chapter 3 Unforeseen Consequences

Basically, you know that after the big elevator with the headcrabs falling on you, there is a security guard on a bridge fighting some creatures, one of them a houndog (or whatever it’s name is) and it blows up some explosive crates, which blows up the bridge and kills the guard, and Gordon then needs to jump on some pipes to make it across. Well, if you kill the houndog, the bridge won’t explode, and the guard won’t die. But there will be an invisible wall that won’t let you cross the bridge, which I think is really inmersion breaking, as the bridge is clear and walkable, and forces you to take the pipe anyways. I can’t upload the screenshot but you can try it for yourself.