it's not about the the number of escapes, it's about whether reasonable and conscious effort is being expended to prevent the escapes.
there could be 1,000 escapes, where each one was enabled by novel and unexpected chain of 0-day exploits. not likely to be considered reckless disregard in court.
there could be 1 escape, where there was no sandbox, no guardrails, no instructions to avoid damage, etc. which would likely to be considered reckless disregard (well, more likely to be, but still, reckless disregard is a high bar).
Surely after 999 escapes, a reasonable person could conclude that the sandbox is not a sufficient precaution?
Are you sure? At some point a reasonable person would conclude that this activity can’t be conducted safely.