I'll give a brief background on the Halpro group for other board members, and then try to answer your questions as best as possible.
After Pearl Harbor, Roosevelt ordered the AAF to mountraids on the Japan, of which the Doolittle Raiders were the most famous. A group, commanded by Col. Harry Halverson and composed of 23 B-24 Liberators, was organized and given the code name "HALPRO" (for Halverson Project). The group left the United States in May 1942 to begin attacks on Japanese targets from a base located in China. When HALPRO arrived in the Egypt, the unit learned that its Chinese base had been captured by the Japanese.
HALPRO was then ordered to remain in place and conduct raids from airfields in Egypt against shipping and North African ports. In June 1942, the Halverson Project was dissolved and the organization was renamed the First Provisional Bombardment Group. Later in 1942 this Group was transferred to the newly activated 376th Heavy Bombardment Group.
Now, on to your questions.Regarding crew briefings, crews were briefed with the best knowledge available at the time, both for the safety of the crew and the effectiveness of the mission.Having said that, in early 1942 strategic long range bombing was in its infancy, and tactics and mission planning evolved thoughout the war.By late in the war mission planners were able to route bombing missions around kow flak installations and known fighter bases, but in early 1942 much of this info was unknown.
Regarding a/c accidents, obviously there are two types: pilot error and non pilot error.Non pilot error could involve such factors as weather, mechanical failure, etc.It was not uncommon to see a/c accidents, and to have a pilot involved in more than one definitely happened.Pilots were well trained in the US before they went overseas, so they were all qualified to handle multi-engine a/c in close formation. Many men were washed out of pilot training who couldn't handle the details of flying, and went on to become effective navigators, bombardiers, etc. Obviously factors such as fatigue, stress and the everpresent cases of "battle fatigue" could affect a pilot's abilities after entering the theatre of operation.
I'm not sure what you're asking about when you mention "handle" friendly fire incidents.The AAF was very accurate in reporting the loss of a/c.I've read numerous Missing Aircraft Reports and Aircraft Accident Reports, and although I've never read a friendly fire report, I've found that the AAF was never squeamish in placing blame on a loss. This info often was not released to the families (morale reasons, obviously), but maintained in internal documents, when known.Withhout knowing the details of the specific incident you mention, it's hard to answer more.
Hope I'm not too far off track in answering your questions,