Well, if you see a very long wick and you cannot see that price in intraday timeframes, then it's just an error in the database.
Take into account that sometimes those long wicks were true, check out some of the flash crashes (you will see then in the intraday timeframes if they are still available online).
If you are using log scale, it will be very annoying so it will call your attention quickly.
If you are using indicators that use high or low as inputs, you will get crazy readings in those indicators.