It's... just barely probable with two people. Assuming 30 whistleblowers, and an actuarial likelihood of 1.2% death[1] in a given year at their ages, we can use binomial probability[2] to determine the chance of two dying in a given year.

The math works out to a 4.4% chance. That's a bit of an eye raiser, but still just believable. (Look, we all believe it can happen we roll a critical in D&D ;)

3 or more dying in a year, we're at 0.5% - I'd really assume that's deliberate.

[1] Actuarial tables: https://www.ssa.gov/oact/STATS/table4c6.html

[2] Calculator if you want to play with probabilities: https://www.wolframalpha.com/input?i=binomial+probability+ca...