Mind if I chime In…
Actually older style split bolts that are copper where not designed to be CU/AL conection choices…The bridge in the middle was still copper and not voiding the copper to aluminum issue…The ones that Speedy and I used today will be listed and labeled as AL/CU if they have that intent…and are usually silver in color ( well the ones I use are…lol…)
Many of the older split bolts that are copper colored did not allow for the mixing…HOWEVER…
With that said…I do not think you should call this out because you are not able to verify the type of split bolt and the electrician is not going to come and cut off the tape to see…so it depends on the installation…
If it was a relative new change over…we have to assume they used a AL/CU rated Split Bolt…but being it is wrapped…no signs of melting tape…due to possible signs of heat build up…a condition that may occure in a situation where disimilar metals happen and resistance could lead to heat built up…sooooooo
so regardless of Alum or Copper Conductors…since you can’t see the end of the conductor to verify if it is Copper Tinned and so on…not enough of something I would call out…sorry…only my opinon.
Never said I was a GURU…just opinionated.
lKnob & tube: 1880’s – 1930’s
lAC (armored cables) 1930’s - current
lNM (non-metallic) cloth covered:1928 – 1960’s
lNM (romex) (plastic sheathed): 1960’s - current
•Copper conductors: 1880’s to current
• Tinned Copper conductors: 1910’s to 1950’s
• Aluminum conductors: 1960’s to current