A man with a light blue t-shirt outside in the open wearing red ear protection while firing a gun.
A man is signaling the start of a race.
Just because, "a man with a light blue t-shirt outside in the open wearing red ear protection while firing a gun," it does not necessarily mean that he is, "signaling the start of a race."
You can fire a gun and not be signaling the start of a race.
The man in the light blue shirt could be firing the gun for fun and might not be signaling the start of a race.