Caltrain is only one line and only about 81 miles of operations, on a single route, with a much higher percentage of grade separation.

Metrolink operates on 7 major routes on the 512 mile on the Metrolink system, with significantly less grade separation, and many more crossings.

Caltrain also has a corridor with virtually no major freight operations or Amtrak operations within in most of that corridor, and that higher mix of freight have either caused or contributed to the severity of damage, in several of the Metrolink accidents.

Luck helps some I guess, and Metrolink seems to have had its share of bad luck, as well as incompetent contractors like Veolia, that didn't help their track record much.

All of these cars, including the bombardier that derailed (also used on Caltrain if I recall correctly?) maintained crashworthiness and structural integrity today.

This isn't the first accident at Rice, which should be grade separated. And, is yet another reason to question spending so much of our scarce public rail budget on a poorly planned, highly speculative, and very expensive super sexy high speed rail system, while neglecting crossing safety on our most heavily used urban and intercity rail corridors.