When my leader first bought VIP, she accidentally clicked max raid when she went to raid x10. She ended up dumping 7k+ stam on tea pots. Everybody laughed, but she was livid... so in a way I can see where you're coming from. A confirmation button would be useful.
I use a tablet, so the buttons are naturally bigger. I haven't had this happen to myself, but I'd be mad too if I did end up hitting max raid when I had a lot saved up.