Blown out of all proportion because Moseley wanted to get his own back on Dennis.
Plenty of teams benefit from moving team members taking information from one team to another.
It is something I would never do, maybe foolishly, since I believe what is in your head is the only thing you can fairly keep, but I know of two very well known engineers who came with complete sets of drawings, and one of them trunks full of actual parts.
The Coughlan/Stepney thing was a witch hunt of McLaren.
Ironically I have been told that the two of them originally hoped to get well paid jobs from another team by bringing both McLaren and Ferrari data, and Mike already had been given the Ferrari data by the time they were refused.
It is true that people push the rules as far as they can, daft not to as long as one stays legal.
As an example, 1mm of front ride height lower is about 0.1 secs quicker so people run as low as they can.
The wooden rubbing strip under the car has an allowable amount of wear, which is checked frequently now the FIA scrutineers know this (they weren't as exigent before...).
The rules originally specified the floor should be rigid, but of course nothing is, and as long as it didn't move when the scrutineers heaved on it, it would pass. Using a sprung stay pre-loaded by about 30kg passed but allowed a front ride height worth 0.7 secs per lap to be run compared to a solid strut. Later there was an automated measuring jig produced which loaded the strut by more than 30kg, showing the front wing as too low in scrutineering so a bit more preload was needed, and so on. The principle being if the car passed the tests it was legal. Nowadays there are loads of load deflection tests specified.