halacha - Is an on-call doctor allowed to read non-emergency text messages on Shabbat?

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?

Answer

It is a Mitzva to desecrate Shabbat to save lives (OC 328:2), even if it is only doubtful if a life is in danger (329:3), and one should even do this Mitzva with alacrity (329:1).

The Shulchan Arukh writes (328:15):

אמדוהו (פירוש התבוננו במחלתו ושיערו) הרופאים שצריך גרוגרת אחת ורצו עשרה והביאו לו כל אחד גרוגרת כולם פטורים ויש להם שכר טוב מאת ה' אפילו הבריא בראשונה:‏
If [the doctors] evaluated that he needed [to eat] one fig [to be healed] and ten people ran and each brought one fig, all of them are exempt [from liability for breaking Shabbat] and they have good reward from God, even if [the sick person] healed after the first one [arrived].

Accordingly, Shemirat Shabbat KeHilchatah (2nd ed. 32:7) rules:

מי שחילל את השבת לצורך פקוח נפש ואחר כך התברר שלא היה צורך בכך, כגון שהשתפר מצבו של החולה, או שהחולה נפטר, או שאדם אחר כבר עשה עבורו את הנדרש לעשות -- אף על פי כן עשה מצוה ויש לו שכר טוב מאה ה' ית' עבור מחשבתו הטובה.‏
Someone who desecrates Shabbat for Pikuach Nefesh and afterwards finds out that there was no need for that action, such as if the sick person already got better, or that the sick person died, or that someone else already did what was needed -- even so he did a Mitzva and he has good reward from God on account of his good intentions.

(See footnote 19 there for more about the nature of this exemption.)

Thus the doctors in your case actually get rewarded for checking their phones to see if there is something that requires their assistance.