Isn't the Citation series in general really intended for dual pilot use?
Hmm, no not really.
First of all, theres a few "Citation" Serieses...the original ones was called the 500 Series. That was the 500/501 (Citation 500/I/ISP), then 550/551 (Citation II/IISP/Bravo) - the stands for the "SP" Models - SP meant Single Pilot. The first evolution was then the S550 (S2) and the 560 (V/Encore/Encore +). For these there still is a single pilot waiver available. Requires training and certain experience (but thats an american thing, as a EASA child Ißm not too familiar with that.)
The 525 series (and the Jet here was a 525C, marketed as CJ4) was the successor of the original series, with different wings, T Tails, engines and of course avionics. it consists of the CJ, CJ1, CJ1+, M2, (C525) the CJ2, CJ2+,(C525A) CJ3 and CJ3 +(C525B) and the CJ4 (C525C). The CJ 4 stands out a little bit, cause its the best performing of the series and the first to have a different wing, basically its a downscaled version of the Sovereign wing (C680). They are all one rating but required differences courses (again: in EASA Land)
In commercial use you would need to fly these with 2 pilots (in EASA land ALL Jets need to be flown with 2 pilots IF commercial). I have flown a lot of single hand on KingAirs and I have about 2000 hrs in a all CJs but the M2, 3+ and 4.
These airplanes are very easy to fly and forgiving. However, the performance especially of the 3 & 4 means that it takes a lot of experience to stay ahead of your airplane IF something goes wrong.
I agree with GF and I think, we are teached to overuse the A/Ps a tad. While I would always try to use as much A/P as possible in a REAL situation, I´d certainly would prefer more training without it. But then, we don´t really know how and how much the pilot in question was trained.