No, I don't agree at all - it would have been accidental and I certainly don't think it would warrant the framing of Bamber. Yes, there might have been an enquiry but given the circumstances, a killer was killed during a siege situation, no careers needed to have been ruined. However, if it is hard for you to believe that Bamber would try and pass off two shots to Sheila as suicide, why would you believe the police would?
However the two shots happened, Bamber would have little choice in going ahead with his plan as you say what other option would he have'?
This is missing the point though. If the police decide to not bother mentioning the second shot - they unwittingly walk in to a Pandora's box situation further down the line. Because by that time, they have gone to inquest regarding Sheila having been killed by a
single gunshot wound and haven't told the press or relatives or Jeremy what happened. Clearly the reason why he blamed the raid team was because he was given the impression somebody was still alive before they went in. That hope was extinguished after they came out. This is suggestive that somebody (probably Sheila) was indeed alive until the raid commenced.
Once they had dug a hole for themselves, they ended up playing in to the chief vulture's hands. Bobby was out and out going to protect the interests of his own brood - not the wishes of June and Nevill.