Identical prices are often a sign of intense competition. Every gas station on a corner has the same price because it's a highly competitive market not because of collusion. The prices of the much more lucrative chocolate bars inside the gas stations are less likely to be identical.

Yes, the gas station example is directly cited in the article I linked to. It’s legal for a gas station owner, with knowledge and consideration of a competitor’s price, to reduce their price to the same or just below. What is illegal is for nominally-competing gas station owners in an area to conspire to keep their prices within a range of each other’s, even without explicit agreement.

"Every gas station on a corner has the same price because it's a highly competitive market not because of collusion."

Huh? I can go to most any gas station-occupied intersection and you will always find two that match and one (usually a Persian-owned Chevron) which is consistently a dollar or more higher per gallon across all grades of fuel.