Alfa Romeo Repair: Belt Problems, unfortunate series of events, second water

Question
Re: 1994 164LS, 24v twin-cam

I have had a nightmarish 5 months of continuing problems going back to a timing belt bearing replacement in May.  Since the bearing and TB were replaced at that time, the water pump has failed twice, the front cams jumped the TB (said to be "impossible") and the serpentine belt failed taking the AC compressor and PS pump with it.   The mechanic who did the work claims "Act of God" but no responsibility on his part.

Last week, another mechanic found the serpentine tensioning spring broken after the second water pump failure.  I'm trying to figure out if this really is an unfortunate series of events or if my (former) mechanic screwed up big time.

Questions:  
1) What relationship would the serpentine have on TB-driven accessories like the WP?  
2) Could the broken SB tensioning spring be a catalyst in these systematic failures?  
3) In your opinion, what could potentially cause the cams to simply jump the TB?

Thanks and best wishes,
Steve L.
San Diego, CA

Answer
1) nothing unless it sends a foreign object into the timing belt cogs.

2) I would have to actually see the mess to make a decision.

3) improper tensioning.  frozen water pump.  foreign object.

I would always replace a water pump that is driven by the cam.