The VANOS internal pressure is 1500+ psi, so yes, there is a good chance the sheared bolt is the cause of it, you may also have a failed o-ring there
Contact beisan and see if they can sell you just the oring and get a new bolt. You should be able to change the o-ring in situ. The issue will be taking a torque wrench there, this bolts are 10NM.
Also remove the solenoid pack (the electronics as you called) as there is a sealing plate, change it for new, it is cheap. This plate is sandwiched between the Valve body and the VANOS unit.
Also check the chain tensioner which has a crush washer that may have failed
Use this guide as reference:
http://beisansystems.com/procedures/..._procedure.htm
Finally, how many miles? These bolts rarely fail, has someone “fixed” your VANoS? How many miles?
Good luck! But it should be easy.
PS. Don't run the engine, and pls check oil level before if you must. Make sure there is oil in it