My shul has a few doctors who carry their cell phones with them. When their phones buzz (B"H, they are smart enough to put the phones on vibrate mode while davening.) with a text message, they, of course, read the message to see if it's an emergency.
Occasionally, the message is NOT an emergency. Granted that they have read it accidentally. I'm curious if even this accidental reading of the message is considered still an aveira (sin). IIRC, there are different categories of "accidents" regarding violation of Shabbat melacha, e.g. - forgetting it was Shabbat, not knowing what you did was forbidden, or accidentally brushing against a light switch & turning on the lights (which is similar to this texting event).
Does this scenario fall into any of those categories?