I'd trust a GC implementation a lot further than I'd trust a typical C programmer. Yes, there's a certain risk that your device will occasionally stop working - but absent formal verification that's a risk for a device who's software is written in any language. Rather than an absolute notion of risk/no risk, let's start talking about acceptable defect rates.
Rust is pretty cool. If I were writing code for a platform like this I might use it (but probably only if I was convinced that GC issues were going to be a real practical problem if I used OCaml/Haskell/Scala-native).