I think people tend to overstate the relationship of past injuries as a predictor of future injuries, and there is some confirmation bias when it plays out that way, vs players who get a few big early career injuries and then stay healthy for a while. Lots of nerve issues are pretty common, and Max's neck problems would probably be looked at as a red flag in retrospect if he ended up injured all the time.
Giving a 7 year deal to any 30 yo power pitcher who's had TJ is probably a bad bet in most cases. It's hard to see how the Nats could have escaped this one. Probably the biggest mistake was signing him to the contract with an option in it. An 8-9 year deal with no options would have left better feelings for everyone involved. But if Boras wasn't willing to go there, then we'd have probably lost Strasburg and not won the world series.
It's crazy how perfectly bad that option contract worked out for the Nats. If the option year was 2018, 2020, 2021, then no way does he excercise it.
The right play was not re-signing him when he optioned out and not signing Rendon, but then we'd all be calling out comparisons to Loria.