Don't know about Howland, both PITT and UCLA got better immediately after he left.
Better? I would disagree with that. Here's Howland's record:
Pittsburgh Panthers (Big East Conference) (1999–2003)
1999–2000 Pittsburgh 13–15 5–11 11th
2000–2001 Pittsburgh 19–14 7–9 5th (West) NIT 2nd Round
2001–2002 Pittsburgh 29–6 13–3 1st (West) NCAA Sweet Sixteen
2002–2003 Pittsburgh 28–5 13–3 T–1st (West) NCAA Sweet Sixteen
Pittsburgh: 89–40 38–26
UCLA Bruins (Pacific-10/12 Conference) (2003–2013)
2003–2004 UCLA 11–17 7–11 T–7th
2004–2005 UCLA 18–11 11–7 T–3rd NCAA 1st Round
2005–2006 UCLA 32–7 14–4 1st NCAA Runner-up
2006–2007 UCLA 30–6 15–3 1st NCAA Final Four
2007–2008 UCLA 35–4 16–2 1st NCAA Final Four
2008–2009 UCLA 26–9 13–5 2nd NCAA 2nd Round
2009–2010 UCLA 14–18 8–10 T–5th
2010–2011 UCLA 23–11 13–5 2nd NCAA 2nd Round
2011–2012 UCLA 19–14 11–7 T–5th
2012–2013 UCLA 25–9 13–5 1st NCAA 1st Round
UCLA: 230–105 118–58
Pitt in the four years after Howland:
2003–04 Pittsburgh 31–5 13–3 1st NCAA Sweet Sixteen
2004–05 Pittsburgh 20–9 10–6 5th NCAA First Round
2005–06 Pittsburgh 25–8 10–6 T–4th NCAA Second Round
2006–07 Pittsburgh 29–8 12–4 T–2nd NCAA Sweet Sixteen
I don't think you can call anything on UCLA in one year, but it seems to me that after Howland rescued Pitt from obscurity he built into a program that continued on the path he created for the next four years, more or less. Can't really say they "got better," IMHO.
As for UCLA, he also rescued them from the dumpster and took them to the NCAA Finals. I predict that they will live to regret hiring Alford as compared to Howland.
I would take him here in a second, and IMHO St John's would be remiss if they aren't doing their due diligence on a coach who has succeeded at the highest levels of the Big East, the Pac-12, and the NCAA tournament.