Are these two hair facts contradictory?

[shikara]

It is recommended that when you wash your hair, you should only use the pads of yiur fingertips on your scalp, and i know that many people just pour diluted shampoo over their heads; however, when ive watched some scritching videos, ive noticed they can be quite aggressive. I guess im trying to determine the best way to make sure i have cleansed my scalp of debris properly and fully.

[Madora]

Dr. Michael always advocated washing with the fingerpads, to avoid damage to the scalp.

[Amber_Maiden]

Dr. Michael always advocated washing with the fingerpads, to avoid damage to the scalp.

This is what I do. I also only shampoo my scalp, unless I'm clarifying.

[Mairéad]

I also only use the pads of my fingers. I can't imagine there being anything stuck on my scalp so badly that I'd have to use my nails.

[Milui Elenath]

For myself I only scritch my scalp when it's dry before I wash. When my scalp is wet it seems easier to damage, perhaps I just don't feel how rough I'm being in the warm water or perhaps it's the water itself, I don't know.

When I wash I am very gentle and use only the pads of my fingers. A clean scalp is important to me because I'm water only.

[spidermom]

I squirt shampoo/water solution all over my scalp, then run my fingers in the direction that my hair is lying, usually from forehead toward nape since I most often wash while standing upright in the shower. I pick up my fingers at the nape and bring them back to the forehead area, moved over a fraction of an inch, until I feel that I've stroked my entire scalp.

Sometimes I use my shower comb instead of my fingers.

[ravenreed]

If I have build up on my scalp, I scritch aggressively. For one thing, it is itchy! Otherwise, I wash with the pads of my fingers.