Why did 405 look so good?

[colly0410]

They did that in the hotel I stayed in in Gran Canaria last year but with an LCD set, just a co-ax lead to it. I was watching SKY news when a moped caused what looked like band 1 type interference, only SKY news was affected, I'm wondering if they were using a band 1 channel modulator & the co-ax was a bit leaky...