Hi Stig,
Luftwaffe reconnaissance pilots regularly carried out anti-shipping attacks, at least in the early war period, so it was not overstepping any boundaries to do so. A few examples from February 1941:
07.02.41: A.Gr. 22 attacked a Handelsschiff with two SC 250 bombs.
11.02.41: 1.(F)/121 attacked two vessels in the Mediterranean
13.02.41: 3.(F)/22 attacked an English submarine
14.02.41: 1.(F)/120 attacked a 600 ton vessel
26.02.41: 3.(F)/22 attacked a 3,000 ton vessel in Moray Firth
27.02.41: 1.(F)/120 attacked a 4,000 ton vessel north of Aberdeen
etc. etc.
Cheers,
Andrew A.
Air War Publications -
www.airwarpublications.com/earticles