As for this:
I don't know about you guys but it looked more like Ash is simply in his battle stance rather than protecting Tomato girl. The camera angle just made it looked like he does. Though again, I can be wrong here since I haven't seen the episode itself, it would help at the very least if someone can provide a gif for us to see how it actually looked like.
The case that I make is that when he's simply in his battle stance, his arms are completely straight. In that image, however, you can see that only the arm opposite Serena is in this "battle stance," while the arm to her side of him is bent. Where it's covering on her in particular (from this angle it looks to be somewhere above the waist) can be debated due to camera angles etc., and while camera angling can make a bent arm appear straight, no camera angle will make a straight arm appear bent: that's simply not how geometry works.