I do have cash to inject if need be.

I think that BiggerPockets has done a lot to inject a good dose of reality into the situation, but there's still a lot of hype out there that can filter in to even the most down-to-earth newbie.

There is little doubt in my mind that he saw a couple guys who he knew had some money, and was looking to inject himself into the business model to extract some of that money.2.

Probably a great place to be injecting right now if you take a little time to know the area and find the best areas to invest in.

Of course you will need to inject some of your own money (down payment) to get a loan.Otherwise, Bill G gave a good response.

There are other options besides a typical bank (hard money, seller financing, etc) that can get you up to 0% down.So, you're saying you got a 95% LTV on a non-owner occupied loan without other collateral injection on your 5th property out of an insured lender, a bank?

You can't inject yourself into the process of handling any tenant complaints unless the compliant is about rent too high or lease renewal etc...UNLESS you can talk the tenants themselves into performing the physical work necessary for the diagnosis of a problem, while you sit back, cross your arms, sipping on a beer while giving the instructions.

Was there equal injections of loan capital from each source?

If you are worried about appreciation, chose a method of investing that injects appreciation with rehab, or if you are worried about appreciation dropping and rents are holding steady and you have cash flow then you are good.  

If you have masonry walls they can drill holes into mortar joints and inject from there.