Just in case the shit did hit the fan it pays to follow some simple rules.
Don't keep decent scales in your house especially not your grow room. You can buy cheap digital kitchen scales at Argos for ~£10 which aren't that accurate, but good enough for me. These should be kept in the kitchen. - Intent to supply
Don't have a large supply of zip lock bags in the house. - Intent to supply
-Edit- stoned minds think alike eh Cowboy
Don't leave records and photo's of your past grows lying around. If you want to keep records do so on your computer and encrypt the files. - Proof of continual growing
The less professional your grow looks the better. Transfer your nutrients into empty tomato feed bottles etc. might make a difference to a judge. They don't like hydro
Say nothing when arrested. contact Release and make sure you have an expert witness for the trial. You can be sure the prosecution will have one.
Its not likely to happen but if it does and your unprepared you can be in deep shit.
Trying to find the link I got some of the above from but can't at the 'mo. If I do I'll post it as it was interesting reading.