I would guess they're worried about breaking something, but thanks for the clarification (and apologies for not having RTFA)
Repairing a leak with an uncertain cause could be at high risk of catastrophic decompression if it was caused by certain types of corrosion or stress.
alt Hacker News
Repairing a leak with an uncertain cause could be at high risk of catastrophic decompression if it was caused by certain types of corrosion or stress.