Because You Can't Rain Check on a Wedding
Question: I missed my high school friend’s wedding this weekend due to an emergency. It’s a pretty good excuse to me, but maybe less so to him. I texted him during the reception to apologize. What else should I do?
Answer: Why on earth would you text someone on his wedding day? Did you think he'd get bored during the best man's toast and covertly check his messages under the table? Were you that afraid of being missed? Unless you were in the bridal party, I promise that he was too busy to notice your absence.
Your text may have been well intentioned, but it likely only caused confusion when it was eventually received (i.e. Wait, Scotty missed the wedding?). After confusion, naturally, comes worry (i.e. Gosh, I hope Scotty's OK). After worry, likely came anger (i.e. How could Scotty miss our wedding?!). Finishing out the cycle, is full-blown resentment (i.e. What a waste of $140 a head it was inviting No-Show Scotty in the first place).
While I personally am quite intrigued to know what such an emergency could have been, your friend, as you duly note, may not find it as justifiable as you do. Spare him the detailed excuses and apologize formally. This will not involve texting.
Write a card addressed to both him and his newly betrothed in which you apologize profusely for missing their special day—something you wouldn't have missed for the world had it not been for [briefly stated reason]. Along with the note, send the most expensive thing still left on their registry. When they post their wedding photos on Facebook a month or two from now, you must like the bejesus out of them.
Do these things and you shall be forgiven.