There are 7 t-states of JNZ instruction when the loop condition becomes false while it is 10 t-states when the condition is true.why is it so?

for eg: JNZ 8050 so when the condition is true it would take

1. opcode fetch- 4T

2. Memory read- 3T

3. memory read- 3T

total 10 T states and when the condition is false it takes

1. opcode fetch-4T

2. 3T states for checking flags and incrementing PC.