Which of the following reactions statements is incorrect?

The yield in Sandmeyer reaction is found to be better than Gattermann reaction.
Iodine is not easily introduced into the benzene ring directly but when the diazonium salt solution is treated with potassium iodide, iodobenzene is formed.
${\mathrm{ArN}}_2^{+}{\mathrm{Cl}}^{-}+\mathrm{KI}\to \mathrm{ArI}+\mathrm{KCl}+{\mathrm{N}}_2$
When arene diazonium chloride is treated with fluoroboric acid, arene diazonium fluoroborate is precipitated which on heating decomposes to yield aryl fluoride
${\mathrm{ArN}}_2^{+}{\mathrm{CI}}^{-}+{\mathrm{HBF}}_4\to \mathrm{Ar}-{\mathrm{N}}_2^{+}{\mathrm{BF}}_4^{-}\stackrel{∆ }{\to }\mathrm{Ar}-\mathrm{F}+{\mathrm{BF}}_3+{\mathrm{N}}_2$
certain mild reducing agents like hypophosphorus acid (phosphoric acid) or ethanol reduce diazonium salts to arenes and themselves get oxidised to phosphorus acid and ethanal respectively.
${\mathrm{ArN}}_2^{+}{\mathrm{CI}}^{-}+{\mathrm{H}}_3{\mathrm{PO}}_2+{\mathrm{H}}_2\mathrm{O}\to \mathrm{ArH}+{\mathrm{N}}_2+{\mathrm{H}}_3{\mathrm{PO}}_3+\mathrm{HCI}$