The amount of effort put into finding multiple critical - high vulnerabilities of a $1TN+ company and the result is $51k + taxes to possibly share between 5 hackers for 4 qualifying bugs for that bounty sounds like Apple took them for a cheap ride through their campus.
Compared to 1 hacker, 1 month, JWT signature check failure = 100k from Apple [0]:
[0] https://bhavukjain.com/blog/2020/05/30/zeroday-signin-with-a...