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Of course, it could have been compressed for you tube too. Experience of running a sound system for DJ's and DJing myself is the mixer headroom is being used. Some mixers are sending +23db at maximum.
If you are controlling the soundsystem you have to reduce the gain on the input from the mixer otherwise you risk hitting the limiters. Then the DJ tries to get more out of the mixer until there's no lower signal at all. Seen it so many times. You can't trust them to keep it in the green.
Also, who's recording it? Venue?