Without further information as to what the exact cause of the accident was, it is very difficult to say whether your claim would be taken on by another law firm, as it all depends on the evidence and the circumstances.
However, a statement made by your employer or work colleague could be considered as being in conflict or even thought of as hostile, and therefore would not carry as much significance as a statement made by someone who is totally independent.
Most law firms will offer a free consultation, so call in and visit or give one of them a call and have a chat, you have nothing to lose.