Can You See It?
We agree with the skepticism, "you can make computer data say anything". We have even been shown so called pressure traces form totally different systems, to those under examination.
When it goes directly into a computer, you have no validation proof.
Oscilloscopes are fine, however when you have to play back to make a comparison, the operator thinks he can get away with showing you anything. There is only one solution. Hard copy, not just hard copy but high paper rate copy. Copy where a full 110 mm width can be allocated to one of multiple channels, where the paper streams out at not less than 200 mm per second, 8 dots per mm, and 250 kHz real time.
In street language that means you can see evidence of events which occur in 0.65 of a millisecond, or you can clearly see 1000 + Hz activity.
The point is that now you have original detailed hard copy, playbacks are easily identifiable and valid at any scale, making truly substantial analysis possible.

Can It Be Detected?
When one dot = 5 "mil" 5/1000th of an inch or 0.125 mm and is equal to 0.00065 seconds, it is essential to take a sample or reading more frequently. Unless the transducers have suitably responsive characteristics, all the best capture and printing, will be worthless.
A suitable transducer specification is:
A. Certified calibrated and with accuracy - including linearity, hysteresis and repeatability to 0.5% FSO
B. Frequency response up to 10kHz
C. 10 Volt DC out
Then from the oscillograph to the computer an IEEE488.1 or similar, parallel interface with a transfer rate of not less than 1 Megabyte per second. All used with signal conditioners of 5 kHz response.

It is easy to hide events and claim success before and after, when one shows pressure before, then flow after.