Which of you two is the lawyer?
Haha, good call. But I'm not a litigator, I just work down the hall from one (of several). I'm also fairly liberal, and believe government does have a place and role in governing society, but still believe we have to always start first and foremost from a principle of individual responsibility.
I have no doubt that the email alerts will be used as ammunition by the plaintiff's lawyer, but the funny thing about that is they are a direct result from Strava's users clamoring for such a feature - i.e. Strava gave its customers what they were asking for - and it strikes me (if the limited information that we have been given on the cyclist is accurate) that this is exactly the kind of feature that this guy was looking for.
If Strava is held liable here, then I could see a real trickle-down effect to a number of other social apps/communities. For instance, my "local" ski resort Mammoth Mountain has an app that keeps track of your top speed, vertical feet in a day/season, etc... Well what happens when someone chasing a record plows into a tree and hurts/kills himself or someone else? Essentially, are we going to outlaw any means of tracking performance in an activity where the activity itself includes some element of danger (which the participants in the activity assume whether or not they are tracking their performance)? Where do you draw the line between encouraging a cyclist to "safely" improve their best time over a route vs. doing so "unsafely?" I don't really think you can. It's the individual's responsibility, not Strava's, to make that distinction.