I believe that when you arrive at the first 100 you'd have 3 50's and no 25's, and thus be unable to provide change for a 100 (no bill combination summing to 75)

bills are 100, 50 and 25. so if anybody paid 25 before the person paying 100, you will have change (4x25, 1x50 and 2x25, etc).

I think this test is wrong:
25
50
25
50
25
50
100
25
50
100
✘ 'NO' should equal 'YES'
When we get to the first 100, we only have bills of 50, so the answer is no