Successful appeals almost always rely on one or two very strong pieces of exculpatory evidence. Bamber hasn't got any so is trying a scattergun approach. Then throw in that he's been illegally silenced - maybe that'll help.
Yes. If I consider, off the top of my head, other high profile cases that have been overturned it has been based on tiny pieces of forensic evidence, often invisible to the naked eye eg:
- Stefan Kiszko - no sperm in semen stain.
- Sally Clarke - bacteria
- Barry George - Gunshot particle
- Sion Jenkins - Expirated blood spatter
- Guildford 4 - Gunshot residue
- Andy Malkinson - DNA evidence
I could go on but the pattern is there.
It should be noted that the above just got on with solving their cases with little or no fanfare.