Tax calculation on allowance position

[InnuceEAN]

Parsing the following position which contains an allowance, but no CategoryTradeTax under the SpecifiedTradeAllowanceCharge element:

<ram:IncludedSupplyChainTradeLineItem>
	...
	<ram:SpecifiedLineTradeAgreement>
		<ram:NetPriceProductTradePrice>
			<ram:ChargeAmount>128.49</ram:ChargeAmount>
			<ram:BasisQuantity unitCode="LTR">100.</ram:BasisQuantity>
		</ram:NetPriceProductTradePrice>
	</ram:SpecifiedLineTradeAgreement>
	<ram:SpecifiedLineTradeDelivery>
		<ram:BilledQuantity unitCode="LTR">56.69</ram:BilledQuantity>
	</ram:SpecifiedLineTradeDelivery>
	<ram:SpecifiedLineTradeSettlement>
		<ram:ApplicableTradeTax>
			<ram:TypeCode>VAT</ram:TypeCode>
			<ram:CategoryCode>S</ram:CategoryCode>
			<ram:RateApplicablePercent>19.00</ram:RateApplicablePercent>
		</ram:ApplicableTradeTax>
		<ram:SpecifiedTradeAllowanceCharge>
			<ram:ChargeIndicator>
				<udt:Indicator>false</udt:Indicator>
			</ram:ChargeIndicator>
			<ram:ActualAmount>3.40</ram:ActualAmount>
			<ram:Reason>Rebate</ram:Reason>
		</ram:SpecifiedTradeAllowanceCharge>
		<ram:SpecifiedTradeSettlementLineMonetarySummation>
			<ram:LineTotalAmount>69.44</ram:LineTotalAmount>
		</ram:SpecifiedTradeSettlementLineMonetarySummation>
	</ram:SpecifiedLineTradeSettlement>
</ram:IncludedSupplyChainTradeLineItem>

The tax on the position is given with 19%, itemTotalNetAmount is quantity * netPrice = 56.69 * 1.2849 = 72.84.
Also there is a rebate of 3.40.
Now the TransactionCalculator is calculating tax on the itemTotalNetAmount without rebate because the "SpecifiedTradeAllowanceCharge" rebate position has no "CategoryTradeTax" and the importer only fetches the tax from the CategoryTradeTax:
ZUGFeRDInvoiceImporter.java#L664

Is this behavior of the parser correct that no tax is calculated for the rebate or should there have been a CategoryTradeTax node under SpecifiedTradeAllowanceCharge? I'm struggling to find any information on which is correct.

The documentation available for download under https://www.ferd-net.de states under "7.1.11 Zuschläge, Abschläge und Rabatte bzw. Ermäßigungen":

Auf Positionsebene, analog zur Rechnungsposition mit gleichem MwSt-Steuersatz wie die Position
(ansonsten müssen sie unabhängig voneinander eingefügt werden

Which might indicate an inheritance of the tax rate from the position, but I don't see any mention in BT-95 for that?