While attacking the Paul's Pages Daily SudokuXP Extreme puzzle, I encountered some difficulty in determining how to apply the BUG rule.

The original puzzle is

030001050004020000900000070800000600700900001002004003050000008000060200090300040

The puzzle in the state that I encountered trouble is

630001052104020000925836174849173625763952481512684793050207008000060200290318540

In this state, all cells have 2 candidates except for R2C7 and R8C3. In each of these two cells, there is 1 candidate that appears 3 times in each row, column, and box that the cell belongs to. Additionally, removing the suspect candidate results in that candidate appearing exactly twice in each row, column, and box (with the exception of the other BUG suspect cell). For R2C7 it's the 9, for R8C3 it's the 7.

Sounds like 2 BUGs to me... except one is and one isn't, and I can't figure out how I'm supposed to identify which is and which isn't. The only reason I know right now is that the program told me that one of them was incorrect.

Can someone take a look and tell me what I'm missing, and what to look for in the future? Thanks...