Unless the case is being investigated by a specific team - such as CID, DV, MIT etc etc - it will stay on the response team with that OIC.
The response team will have about 20 cops on it - each cop will be carrying a case load of about 15-20 jobs each. Each job will need enquiries doing and case files to be completed and sent to CPS. Add into this the constant incoming emergency jobs, priority jobs, more jobs with enquiries attached, missing from homes, cell watches, hospital watches, sudden deaths, MH etc etc. You don't really get chance top do your own jobs let alone other peoples.
So you can't just pass your 15-20 jobs onto you team mates when your off. There will be about 5-6 abstractions from the shift at any one time - so that will be about 100 enquiries which will have to re-distributed around the shift.
It doesn't work that way.
Unless its a significant job which you can pass to a designated team - it stays with you to sort out. The other cops on the team won't get chance to do anything with it in any case as they have their own cases to sort out. If you're lucky, you might have a cop on light duties or office bound who can sort out some of the admin for you - but that's about it.
7 weeks away. Yes not a very common occurrence to have 7 weeks on holiday, but it can happen if its planned and approved. This will cover things like a wedding and honeymoon in Australia for example. It may be a case that the OIC is away from shift for 7 weeks - so a 2 week holiday followed by a 4 week course, blue light driving courses take 4 weeks to run usually.
We don't know what the enquiries are - the phone down loads take ages to come back. For it to go to CPS, they have to be professionally downloaded and a report supplied by an authorising body - often having to go through RIPA for approval. Its not just a 'quick look'. The police may have had a 'quick look' at CF's phone for the purpose of the interview, but that's not good enough for a case file.
Then the case file has to be assembled & redacted and sent to CPS. CPS have a month turnaround, but that often gets delayed as they have staff shortages. This is possibly what the delay is for and the increase in the bail time.